import 'dart:io';
  
void main() {
  Calculator c1=new Calculator();
  int res = c1.Sum(1, 2);
  print(res);
  
}

class Calculator{
  int Sum(int n1, int n2){
    return n1+n2;
    
  }
    int Mul(int n1, int n2){
    return n1*n2;
    
  }
    double Div(int n1, int n2){
    return n1/n2;
    
  }
    int Sub(int n1, int n2){
    return n1-n2;
    
  }
  
  
}