diff --git a/src/index.js b/src/index.js
index ac593f4..709ddf1 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,11 +1,70 @@
 // Entry
-class Entry {}
+class Entry {
+    constructor (date, amount, description){
+        this.date = date;
+        this.amount = amount;
+        this.description = description;
+    }
+        getFormattedAmount (){
+            return `${this.amount} €`
+        }
+}
+
+let amount = 100;
+
 
 // Income
-class Income {}
+class Income extends Entry {
+    constructor (date, amount, description){
+        super(date, amount, description)
+        this.type = `income`;
+    }
+}
 
 // Expense
-class Expense {}
+class Expense extends Entry {
+    constructor (date, amount, description, paid){
+        super (date, amount, description, paid)
+        this.paid = paid;
+        this.type = "expense"
+    }
+     getFormattedAmount (){
+            return `-${this.amount} €`
+        }
+    }     
+    
+    amount = 99;
+
 
 // Budget
-class Budget {}
+class Budget {
+    constructor(){
+        this.entries=[];
+    }
+
+    addEntry(entry) {
+        this.entries.push(entry);
+    }
+    
+    getCurrentBalance(){
+      if (this.entries.length === 0){
+        return 0;
+      }
+
+      let total = 0;
+
+      for (let i=0; i<this.entries.length; i++){
+        let amounts = this.entries[i];
+        if(amounts.type === "income"){
+            total += amounts.amount;
+            } else if (amounts.type === "expense"){
+                total -=amounts.amount;
+            }
+        }
+         return total;
+      }
+    
+    }
+  
+
+