#include<stdio.h>

void rr_scanl(int index, int *numBox) {
	char str;
	for (int i = 0; i<index; i++)
		numBox[i] = 0;
	int cnt = 0;
	int mode = 0;
	while (cnt < index) {
		str = getchar();
		if (str == '\n') {
			if (cnt != 0)
				break;
		}
		else if (str < '0' || str > '9') {
			if (str == '-')
				mode = 1;
			cnt++;
		}
		else {
			if(mode == 0)
				numBox[cnt] = numBox[cnt] * 10 + (int)str - (int)'0';
			else
				numBox[cnt] = numBox[cnt] * 10 - ((int)str - (int)'0');
		}
	}
}

int main() {
	
	int yukiAns = 0;
	int ans = 0;
	int num = 0;
	int unit[10000];

	scanf("%d", &num);
	rr_scanl(num, unit);
	scanf("%d", &yukiAns);

	for (int i = 0; i < num; i++)
		ans += unit[i];

	printf("%d", ans - yukiAns);

	// 終了コードは0
	return 0;
}