#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <iomanip>
#include <cmath>
#include <functional>
using namespace std;
#define diff(x,y) ((x > y) ? (x - y) : (y - x))
#define us(x) ((x > 0) ? x : x * -1)
#define change(x) (x ? false : true)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define lli long long int
const lli mod = 1e9 + 7;


int main() {
	int n, m, v, w;
	cin >> n >> m;
	vector <int> x(n);
	rep(i, n) {
		x[i] = i + 1;
	}
	rep(i, m) {
		cin >> v;
		v--;
		w = x[v];
		//cout << w << endl;
		x.erase(x.begin() + v);
		x.insert(x.begin(), w);
	}
	cout << x[0] << endl;
	return 0;
}