#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
int main(void)
{
    int totalnum,num,yukians,trueans=0;
    scanf("%d",&totalnum);
    for(int i=0;i<totalnum;i++)
    {
        scanf("%d",&num);
        trueans+=num;
    }
    scanf("%d",&yukians);
    printf("%d",trueans-yukians);
    
}