switch

#include<cstdio>
int main(){
    int a,b,c,d;
    scanf("%d %d %d %d",&a,&b,&c,&d);
    switch(a+b+c+d){
        case 0:printf("0");break;
        case 1:printf("1");break;
        case 2:printf("2");break;
        case 3:printf("1");break;
        case 4:printf("0");break;
    }
}