#include<bits/stdc++.h>
using namespace std;
int main(){
    int g,w,b,x,s;
    scanf("%d %d %d %d",&g,&w,&b,&x);
    g=x%10;
    w=x/10%10;
    b=x/100;
    s=g+s+b;
    printf("%d",s);
}
/**************************************************************
	Problem: 1027
	User: xuezihong1
	Language: C++
	Result: Wrong Answer
****************************************************************/