#include <stdio.h>

int main(void)
{
	int i,n,tmp;
	long int sum =0, yuki;

	scanf("%d", &n);
	for(i=0; i<n; i++){
		scanf("%d", &tmp);
		sum += tmp;
	}
	scanf("%ld", &yuki);
	printf("%ld\n", sum-yuki);
	return 0;
}