diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/app/data/sum.txt b/app/data/sum.txt
new file mode 100644
index 0000000..91498a5
--- /dev/null
+++ b/app/data/sum.txt
@@ -0,0 +1 @@
+1,2,7,20,56,22
\ No newline at end of file
diff --git a/app/data/zadanie01/sum.txt b/app/data/zadanie01/sum.txt
index e69de29..615088b 100644
--- a/app/data/zadanie01/sum.txt
+++ b/app/data/zadanie01/sum.txt
@@ -0,0 +1 @@
+108
\ No newline at end of file
diff --git a/app/data/zadanieDnia/test.txt b/app/data/zadanieDnia/test.txt
index 47c17e3..0bcff2e 100644
--- a/app/data/zadanieDnia/test.txt
+++ b/app/data/zadanieDnia/test.txt
@@ -1,7 +1,7 @@
-You Don't Know JS: ES6 & Beyond
-Foreword
+yOu dOn't kNoW Js: Es6 & BeYoNd
+fOrEwOrD
 
-Kyle Simpson is a thorough pragmatist.
+kYlE SiMpSoN Is a tHoRoUgH PrAgMaTiSt.
 
-I can't think of higher praise than this. To me, these are two of the most important qualities that a software developer must have. That's right: must, not should. Kyle's keen ability to tease apart layers of the JavaScript programming language and present them in understandable and meaningful portions is second to none.
-[https://github.com/getify/You-Dont-Know-JS/blob/master/es6%20%26%20beyond/foreword.md]
\ No newline at end of file
+i cAn't tHiNk oF HiGhEr pRaIsE ThAn tHiS. tO Me, ThEsE ArE TwO Of tHe mOsT ImPoRtAnT QuAlItIeS ThAt a sOfTwArE DeVeLoPeR MuSt hAvE. tHaT'S RiGhT: mUsT, nOt sHoUlD. kYlE'S KeEn aBiLiTy tO TeAsE ApArT LaYeRs oF ThE JaVaScRiPt pRoGrAmMiNg lAnGuAgE AnD PrEsEnT ThEm iN UnDeRsTaNdAbLe aNd mEaNiNgFuL PoRtIoNs iS SeCoNd tO NoNe.
+[hTtPs://gItHuB.CoM/GeTiFy/yOu-dOnT-KnOw-jS/BlOb/mAsTeR/Es6%20%26%20BeYoNd/fOrEwOrD.Md]
\ No newline at end of file
diff --git a/app/zadanie01.js b/app/zadanie01.js
index 8c20173..57c2725 100644
--- a/app/zadanie01.js
+++ b/app/zadanie01.js
@@ -1 +1,25 @@
-//Twój kod
\ No newline at end of file
+const fs = require('fs');
+
+fs.readFile('../app/data/zadanie01/input.json', 'utf8', (err, data) => {
+            if (err === null){
+            console.log('Poprawnie odczytano plik.', data);
+            let arr = JSON.parse(data);
+            function sum (x){
+                let y= 0;
+                for (i=0; i<arr.length; i++) {
+                    y +=arr[i];
+                }
+                return y;
+            }
+                    fs.writeFile('../app/data/zadanie01/sum.txt', sum(arr), err => {
+                        if (err === null){
+                        console.log('Zapisano sumę poprawnie!');
+                    } else {
+                        console.log('Błąd podczas zapisu sumy w pliku!', err);
+                    }
+                });
+
+        } else {
+            console.log('Błąd podczas odczytu pliku jSON!', err);
+        }
+});
\ No newline at end of file
diff --git a/app/zadanie02.js b/app/zadanie02.js
index 8c20173..1c226d9 100644
--- a/app/zadanie02.js
+++ b/app/zadanie02.js
@@ -1 +1,19 @@
-//Twój kod
\ No newline at end of file
+const fs = require('fs');
+
+fs.readdir('../app/data/zadanie02', (err, files) => {
+    if (err === null){
+    files.forEach(file => {
+        fs.readFile('../app/data/zadanie02/'+file, 'utf8', (err, data) => {
+            if (err === null){
+                console.log(data);
+            } else {
+                console.log('Błąd podczas odczytu pliku!', err);
+            }
+        });
+
+
+});
+} else {
+    console.log('Błąd podczas listowania katalogu!', err);
+}
+});
\ No newline at end of file
diff --git a/app/zadanieDnia.js b/app/zadanieDnia.js
index 8c20173..d62cc71 100644
--- a/app/zadanieDnia.js
+++ b/app/zadanieDnia.js
@@ -1 +1,52 @@
-//Twój kod
\ No newline at end of file
+const fs = require('fs');
+
+function TrAwKa(fileName) {
+    fs.readFile(fileName, 'utf8', (err, data) => {
+        if (err === null) {
+            let text = '';
+            for (let i = 0; i < data.length; i++) {
+                if (i % 2 !== 0) {
+
+                    text += data[i].toUpperCase();
+                }
+                else {
+                    text += data[i].toLowerCase();
+                }
+            }
+            return fs.writeFile(fileName, text, err => {
+                if (err === null) {
+                    console.log('Plik został zmieniony w nieskoszoną TrAwKę:' + '\n\n' + text);
+                } else {
+                    console.log("błąd zapisu", err);
+                }
+            })
+        } else {
+            console.log('Błąd podczas odczytu pliku!', err);
+        }
+    });
+}
+
+TrAwKa(process.argv[2]);
+
+// //version 2:
+// const fs = require('fs');
+// function TrAwKa(fileName) {
+//     fs.readFile(fileName, 'utf8', (err, data) => {
+//         if (err === null) {
+//             let text = '';
+//             [...data].forEach((e, i) => {
+//                 text += (i % 2 === 0) ? e.toUpperCase() : e.toLowerCase();
+//             });
+//             fs.writeFile(fileName, text, err => {
+//                 err === null? console.log('Plik został zmieniony w nieskoszoną TrAwKę:' +'\n\n'+ text) : console.log('Błąd zapisu pliku')
+//             })
+//         } else {
+//             console.log('Błąd odczytu pliku')
+//         }
+//     });
+// }
+// TrAwKa(process.argv[2]);
+
+
+
+