#include <iostream>
#include <vector>
using namespace std;
int main(int argc, char* argv[])
{
	int N,M;
	cin>>N>>M;
	vector<int> Val;
	int i;
	for (i=1;i<=N;i++){
		Val.push_back(i);
	}
	int A;
	for (i=0;i<M;i++){
		cin>>A;
		int v=Val[A-1];
		Val.erase(Val.begin()+A-1);
		Val.insert(Val.begin(),v);
	}
	cout<<Val[0]<<endl;
	return 0;
}