include <stdio.h>

int main() { int a,b,c,d,s; //scanf("%d %d %d %d %d",&a,&b,&c,&d,&s); scanf("%d %d %d %d %d",&a,&b,&c,&d,&s); if((a+b==s)||(a+c==s)||(a+d==s)||(c+b==s)||(d+b==s)||(c+d==s)) {

printf("1");

} else {

printf("-1");

} return 0; }