#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i < b; i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(int i = a; i >= b; i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()
using namespace std;

using lint = long long;
using ld = long double;

int INF = 2000000000;
lint LINF = 1000000000000000000;

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> v(n);
    rep(i, n) {
        v[i] = i;
    }
    while (m--) {
        int a;
        cin >> a;
        a--;
        vector<int> nv;
        nv.emplace_back(v[a]);
        rep(i, a) {
            nv.emplace_back(v[i]);
        }
        For(i, a + 1, n) {
            nv.emplace_back(v[i]);
        }
        swap(v, nv);
    }
    cout << v[0] + 1 << endl;
}