#include<stdio.h>
int main(void){
	long suc=0,ans;
	int n,i;
	int a[10000];
	scanf("%d",&n);
	for(i=0;i<n;i++){
		scanf("%d",&a[i]);
		suc += a[i];
	}
	scanf("%ld",&ans);
	printf("%ld\n",suc - ans);
	return 0;
}