#include <stdio.h>

int main(void)
{
	long n, v;
	long total = 0;
	long i, j;

	scanf("%ld", &n);

	for (i = 0; i < n; i++){
		scanf("%ld", &j);
		total += j;
	}

	scanf("%ld", &v);

	printf("%ld\n", total - v);

	return 0;
}