diff --git a/calc/main.swift b/calc/main.swift
index f3612d3..259e307 100644
--- a/calc/main.swift
+++ b/calc/main.swift
@@ -8,7 +8,185 @@
 
 import Foundation
 
-var args = ProcessInfo.processInfo.arguments
-args.removeFirst() // remove the name of the program
+class Equation{
+    var args:[String]
+    var result:Int
+    
+    init(args:[String]) {
+        self.args=args
+        self.result=0
+    }
+    
+    func isValid() -> Bool{
+        var valid = false
+        for i in 0...args.count-1{
+            let num = Int(args[i])
+            if (args[i]=="+" || args[i]=="-" || args[i]=="x" || args[i]=="/" || args[i]=="%"){
+                valid = true
+            }
+            else if num != nil
+            {
+                valid = true
+            }
+            else{
+                valid = false
+                break;
+            }            
+        }
+        return valid
+    }
+    
+    func highOperationValue() -> Bool{
+        var isHight = false
+        if args.count>2{
+            for i in 0...args.count-1{
+                if(args[i]=="x" || args[i]=="/" || args[i]=="%"){
+                    isHight = true
+                    break
+                }
+            }
+        }
+        return isHight
+    }
+    
+    func newArgs(value:String,pos:Int) -> [String]{
+        var new : [String] = []
+        if(pos > 1){
+            for a in 0...pos-2{
+                new.append(args[a])
+            }
+        }
+        new.append (value)
+        if(pos != args.count-2){
+            for b in pos+2...args.count-1{
+                new.append(args[b])
+            }
+        }
+        return new
+    }
+    
+    func multiplyDivideModulus(){
+        for i in 1...args.count-1{
+            if args[i] == "x"{
+                args = newArgs(value: String(Int(args[i-1])! * Int(args[i+1])!), pos: i)
+                break
+            }
+            if args[i] == "/"{
+                if args[i+1] == "0"{
+                     //args = newArgs(value: String(Int(args[i-1])! / Int(args[i+1])!), pos: i)
+                    print("Division by zero")
+                    exit(4)
+                }else{
+                    args = newArgs(value: String(Int(args[i-1])! / Int(args[i+1])!), pos: i)
+                    break
+                }
+            }
+            
+            if args[i] == "%"{
+                if args[i+1] == "0"{
+                    //args = newArgs(value: String(Int(args[i-1])! / Int(args[i+1])!), pos: i)
+                    print("Module by zero")
+                    exit(4)
+                }else{
+                    args = newArgs(value: String(Int(args[i-1])! % Int(args[i+1])!), pos: i)
+                    break
+                }
+            }
+            
+        }
+    }
+    func addAndSubtract(){
+        result = Int(args[0])!
+        if args.count > 1 {
+            for i in 1...args.count-1{
+                if args[i] == "+"{
+                    result += Int(args[i+1])!
+                }
+                if args[i] == "-"{
+                    result -= Int(args[i+1])!
+                }
+            }
+        }
+    }
+    func prntRes() {
+        print("\(result)")
+    }
+}
+
+func getargs() -> [String]{    
+    var args = ProcessInfo.processInfo.arguments
+    args.removeFirst() // make the args ready
+    return args
+}
+func getInput() ->  [String] {
+    
+    //print("Please enter numbers to calculate: ")
+    let inputString: String? = String(readLine()!)
+    
+    if inputString == nil {
+        print("Input was not a number")
+        exit(1)
+    }
+    
+    guard let input = inputString else { return [] }
+    
+    var inputText = input.split{$0 == " "}.map(String.init)
+    if inputText.count>0 {
+        //print(inputText)
+        inputText.removeFirst() // make the args ready
+    }
+    return inputText
+}
+
+
+func validArgs (arg:String) -> Bool{
+    if arg=="+" || arg=="-" || arg=="x" || arg=="/" || arg=="%" || Int(arg) != nil {
+        return true
+    }else{
+        return false
+    }
+}
+
+func main() ->  [String] {
+     let args = getargs()
+    if args.count>0 {
+        return args
+    }
+    else{
+        return getInput()
+    }
+}
+
+//1: If you want to run in Terminal Use 1 Uncomment below
+//var equation: Equation = Equation(args: getInput()) //1
+//2: If you need to Work for TestCases Use 2 Uncomment below
+//var equation: Equation = Equation(args: getargs()) //2
+
+//Main
+var equation: Equation = Equation(args: main()) //2
+if equation.args.count > 0{
+//    let result = Int(equation.args[0])
+    /*if equation.args.count < 3{
+        print("Incomplete ")
+        exit(2)
+    }else*/
+    if equation.args.count == 2{
+        print("Invalid inputs")
+        exit(2)
+    }
+    else if !equation.isValid(){
+        print("Invalid ")
+        exit(3)
+    }else{
+        while equation.highOperationValue(){
+            equation.multiplyDivideModulus()
+        }
+        equation.addAndSubtract()
+        equation.prntRes()
+    }    
+}
+else {
+    print("Invalid inputs")
+    exit(2)
+}
 
-print(Int(args[0])!)