#include<stdio.h>

int main(void) {
	int kosu, kazu,kazu_, yuki;

	scanf("%d\n", &kosu);

	for (int i = 0; i < kosu; i++) {
		scanf("%d", &kazu_);
		kazu = kazu + kazu_;
		//printf("%d  ",kazu_);
		//fflush(0);
	}
	scanf("\n");
	scanf("%d", &yuki);

	printf("%d", kazu - yuki);
}