#include <bits/stdc++.h>
// #include <boost/multiprecision/cpp_int.hpp>
using namespace std;
// using bigint = boost::multiprecision::cpp_int;

template <typename T> using min_priority_queue = priority_queue<T,vector<T>,greater<T>>;

random_device seed_gen;
mt19937 engine(seed_gen());

int64_t get_time_ns(){
    struct::timespec t;
    clock_gettime(CLOCK_MONOTONIC, &t);
    return t.tv_sec * int64_t(1'000'000'000) + t.tv_nsec;
}

void f(vector<int> &v, int i) {
    for(int j = i; j >= 1; j--) {
        swap(v[j], v[j-1]);
    }
}

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> A(m);
    for(int &a : A) {
        cin >> a;
        a--;
    }

    vector<int> v(n);
    for(int i = 0; i < n; i++) v[i] = i+1;
    for(int a : A) {
        f(v, a);
    }
    cout << v[0] << endl;
    return 0;
}