#include <iostream>
#include <vector>
using namespace std;
 
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;
    vector<int> now;
    for(int j = M ; j < N ; j ++){
      now.push_back(A[j]);
    }
    for(int j = 0 ; j < M ; j ++){
      now.push_back(A[j]);
    }
//    for(int j = 0 ; j < now.size(); j++)
//      cout<<now[j]<<" ";
//    cout<<endl;
    A = now;
    
  }
  cout<<A[0]<<endl;
}