#include <stdio.h>
#include <stdlib.h>
int main(){
  int N,b;
  int i,result;
  int *a;
  scanf("%d",&N);

  a = (int*)malloc (sizeof(int)*N);
  for(i=0;i<N;i++){
    scanf("%d",&a[i]);
  }
  scanf("%d",&b);
  result = 0;
  for(i=0;i<N;i++){
    result += a[i];
  }
  printf("%d\n",result-b);

  
  return 0;
}