Codeforces 228A. A.Is your horseshoe on the other hoof? Solution

Solve in C++:

//AH Tonmoy
//Department of CSE ,Islamic University

#include<bits/stdc++.h>
using namespace std;
int main()
{

    int s1,s2,s3,s4,c=0,s[100]= {0},i,j;
    for(i=0; i<4; i++)
    {
        cin>>s[i];
    }
    sort(s,s+4);
    for(i=0; i<4; i++)
    {

        if(s[i]==s[i+1])
            c++;
    }
   cout<<c<<endl;
   c=0;

}