#include <iostream> 
using namespace std; 
int main () { 
    int a = 3; 
    int b = 5; 
    cout<<"a="<<a<<",b="<<b<<endl; 
    a = a+b;    ///a=7 
    b = a-b;    ///b=3; 
    a = a-b;    ///a=5 
    cout<<"a="<<a<<",b="<<b<<endl; 
    return 0; 
}