#include <stdio.h>

int main(void)
{
    int c,i,y;
    int j = 0;
    scanf("%d",&i);
    int a[i];
    for (c = 0; c < i; c++) {
        scanf("%d",&a[c]);
        j = j + a[c];
    }
    scanf("%d",&y);
    printf("%d\n",j - y);
    return 0;
}