#include <iostream>
using namespace std; 
int main() {
    int a, b, c, d; 
    cout <<"Enter the four values :"<<endl ;
    cin >>a>>b>>c>>d; 
    cout <<"a="<<a<<"\t b="<<b<<"\t c="<<c<<"\t d="<<d<<endl; 
    if (a>b&&a>c)
    {
        if (a>d)
        {
            cout <<"Greatest number is a";
        }
        else 
        cout <<"Greatest number is d";
    }
    else if (b>c&&b>d)
    {
        cout <<"Greatest number is b";
        
    }
    else if (c>d)
    {
        cout <<"Greatest number is c";
    }
    else
    cout <<"Greatest number is d";
    return 0;
}