SOLUTION OF URI 1930

//    Solution of  1930 Electrical Outlet
//   (Mahmud_Jamil) BRUR






#include <stdio.h>
int main()
{
    int a,b,c,d,e;
    scanf("%d%d%d%d", &a, &b, &c, &d);
    e=a+b+c+d-3;
    printf("%d\n", e);
    return 0;
}