#include <bits/stdc++.h>
#define INF INT_MAX / 2
#define MOD 1000000007

using namespace std;

typedef pair<int,int> PII;
typedef pair<int,pair<int,int>> PIPII;
typedef long long ll;

int main(void) {
	int n,m;
	cin >> n >> m;
	vector<int> a(n);
	for(int i=0;i<n;i++){
		a[i] = i+1;
	}
	for(int i=0;i<m;i++){
		int num;cin >> num;
		int tmp = a[num-1];
		for(int i=num-2;i>=0;i--){
			a[i+1] = a[i];
		}
		a[0] = tmp;
	}

	cout << a[0] << endl;

}