#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; i++)

int main() {
    cin.tie(nullptr);
    
    int N, M;
    cin >> N >> M;
    
    vector<int> num(N);
    rep(i, 0, N) num[i] = i;
    
    rep(i, 0, M) {
        int A;
        cin >> A;
        A--;
        
        int tmp = num[A];
        for (int i = A; i > 0; i--) {
            num[i] = num[i - 1];
        }
        
        num[0] = tmp;
    }
    
    cout << num[0] + 1 << '\n';
}