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..83474ce 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..306c886 100644
--- a/app/zadanie01.js
+++ b/app/zadanie01.js
@@ -1 +1,19 @@
-//Twój kod
\ No newline at end of file
+//Twój kod
+const fs = require('fs');
+
+fs.readFile('./data/zadanie01/input.json', 'utf8', (err, data) => {
+    if (err === null){ 
+        console.log('Poprawnie odczytano plik.', data);
+        let dataParsed = JSON.parse(data);
+        var sum = dataParsed.reduce((prev,curr)=>{return prev+curr})
+        fs.writeFile('./data/zadanie01/sum.txt', sum, err => {
+            if (err === null){
+                console.log("Sukces!");
+    } else { 
+        console.log('Błąd podczas odczytu pliku!', err);
+    }
+    });
+    }else{ 
+        console.log('Błąd podczas odczytu pliku!', err);
+    }
+});
diff --git a/app/zadanie02.js b/app/zadanie02.js
index 8c20173..0006575 100644
--- a/app/zadanie02.js
+++ b/app/zadanie02.js
@@ -1 +1,19 @@
-//Twój kod
\ No newline at end of file
+//Twój kod
+const fs = require('fs');
+
+//Odczytaj listę plików i folderów...
+fs.readdir('./data/zadanie02/', (err, files) => {
+    if (err === null){
+        files.forEach( file => {
+            fs.readFile(`./data/zadanie02/${file}`, 'utf8', (err, data) => {
+                if (err === null){
+                    console.log(`Poprawnie odczytano plik ${file}. Dane z pliku: `, data);
+                } else {
+                    console.log('Błąd podczas odczytu pliku!', err);
+                }
+            });
+        });
+    } else {
+        console.log('Błąd podczas listowania katalogu!', err);
+    }
+});
\ No newline at end of file
diff --git a/app/zadanieDnia.js b/app/zadanieDnia.js
index 8c20173..b2c7ba7 100644
--- a/app/zadanieDnia.js
+++ b/app/zadanieDnia.js
@@ -1 +1,26 @@
-//Twój kod
\ No newline at end of file
+//Twój kod
+
+const fs = require('fs');
+fs.readFile(`./data/zadanieDnia/${process.argv[2]}`, 'utf8', (err, data) => {
+    if (err === null){ 
+        console.log('Poprawnie odczytano plik.', data);
+        var letter = []
+        for(let i=0; i<data.length;i++){
+            if(i%2===0){
+                letter.push(data[i].toUpperCase())
+            }else{
+                letter.push(data[i].toLowerCase())
+            }
+        }
+        let sentence =  letter.join("");
+        fs.writeFile(`./data/zadanieDnia/${process.argv[2]}`, sentence, err => {
+            if (err === null){
+                console.log("Sukces!");
+    } else { 
+        console.log('Błąd podczas odczytu pliku!', err);
+    }
+    });
+    }else{ 
+        console.log('Błąd podczas odczytu pliku!', err);
+    }
+});