#include <iostream>

using namespace std;

int main()
{
   int a;
   int b;
   int c;
   cout<<"vvedi 1e chislo: ";
   cin>>a;
   cout<<"vvedi 2e chislo: ";
   cin>>b;
   cout<<"wwedi 1 chtob naiti summu, 2 chtobi naiti raznicu, 3 dlya deleniya: ";
   cin>>c;
   switch(c){
   case 1: cout<<a+b; break;
   case 2: cout<<a-b; break;
   case 3: cout<<a/b; break;
   }
    return 0;
}