#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(void){
  int n, m;
  cin >> n >> m;
  int c[n];
  for(int i = 0; i < n; i++) c[i] = i + 1;
  int A[m];
  for(int i = 0; i < m; i++) cin >> A[i];
  for(int i = 0; i < m; i++){
    int ptr = A[i] - 1;
    int temp = c[ptr];
    for(int j = ptr; j > 0; j--){
      c[j] = c[j - 1];
    }
    c[0] = temp;
  }
  cout << c[0] << endl;
  return 0;
}