#include <iostream>
#include <math.h>
#include <string.h>

using namespace std;

int main()
{
    int a,b;  //Calculeaza media aritmetica, media geometrica sau a mod b la alegere
    char c[2];
    cout<<"Ce operatie doriti?"<<endl;
    cout<<"a=";
    cin>>a;
    cout<<"b=";
    cin>>b;
    cout<<"c=";
    cin.ignore();
    cin.getline(c,2);
    if(c[0]=='x') cout<< (a+b)/2;
    else if(c[0]=='y')
        cout<< (sqrt(a*b));
    else if(c[0]=='z')
        cout<< a%b;
    else cout<<"Alegere gresita!";
    return 0;
}