#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
  int n;
  scanf("%d", &n);
  
  int sum = 0;

  for (int i=0; i<n; i++) {
    int temp;
    scanf("%d", &temp);
    sum += temp;
  }

  int otherSum = 0;
  for (int i=0; i<n-1; i++) {
    int temp;
    scanf("%d", &temp);
    otherSum += temp;
  }

  printf("%d\n", sum - otherSum);

  return 0;
}