#include <stdio.h>

int main(void)
{
	int index;
	scanf("%d", &index);

	int ans = 0;
	int num[index];
	int i;
	for (i = 0; i < index; i++) {
		scanf("%d", &num[i]);
		ans += num[i];
	}

	int wrongans;
	scanf("%d", &wrongans);

	printf("%d\n", ans - wrongans);

	return 0;
}