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

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> as;
    for (int i = 1; i <= n; i++)
        as.push_back(i);
    for (int i = 0; i < m; i++) {
        int a, x;
        cin >> a;
        x = as[a-1];
        as.erase(as.begin() + a-1);
        as.insert(as.begin(),x);
    }
    cout << as[0] << endl;
    return 0;
}