#include <stdio.h>
int main()
{
  int N, v, sum = 0;
  scanf("%d", &N);
  for (int i = 0; i < N; i++)
  {
    int num = 0;
    scanf("%d", &num);
    sum += num;
  }
  scanf("%d", &v);
  printf("%d\n", sum - v);
  return 0;
}