#include <iostream>
#include <list>
#include <iterator>
#include <algorithm>
#include <numeric>

using namespace std;

int main(){
    int n, m;
    list<int> cards;
    
    cin >> n >> m;
    cards.resize(n);
    iota(cards.begin(), cards.end(), 1);
    
    for(int i=0; i<m; i++){
        int a;
        cin >> a;
        auto it = std::next(cards.begin(), a-1);
        int card = *it;
        cards.erase(it);
        cards.push_front(card);
    }
    
    cout << cards.front() << endl;
}