#include <iostream>


using namespace std;


int main()
{
    int petka=0;
    int glava=0;
    int a, b, c, d;


    cin>>a>>b>>c>>d;
    if(a==0){
        glava+=1;
    }
    else{
        petka+=1;
    }
        if(b==0){
        glava+=1;
    }
    else{
        petka+=1;
    }
        if(c==0){
        glava+=1;
    }
    else{
        petka+=1;
    }
        if(d==0){
        glava+=1;
    }
    else{
        petka+=1;
    }


if(petka>glava)
cout<<4-petka<<endl;
else
    cout<<4-glava<<endl;


   return 0;
}