#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
#include <iomanip>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETSEGMENT( A , SEPARATOR ) string A; getline( cin , A , SEPARATOR ) 
#define GETLINE( A ) string A; getline( cin , A ) 
#define FOR_LL( VAR , INITIAL , FINAL_PLUS_ONE ) for( ll VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ )
#define MIN( A ) if( A < min ){ min = A; } 
#define MAX( A ) if( max < A ){ max = A; } 
#define MINMAX( A ) MIN( A ); MAX( A ) 
#define RETURN( LL , ANSWER ) const LL answer_for_contest = ( ANSWER ); cout << answer_for_contest << endl; return 0 
#define DOUBLE( DIGITS , ANSWER ) const double answer_for_contest = ( ANSWER ); cout << fixed << setprecision( DIGITS ) << answer_for_contest << endl; return 0 

template <typename T> inline T Distance( const T& a , const ll& b ){ return a < b ? b - a : a - b; }

int main()
{

  CIN( ll , N );
  list<ll> C{};
  N++;
  FOR_LL( i , 1 , N ){
    C.push_back( i );
  }
  CIN( ll , M );
  FOR_LL( i , 0 , M ){
    CIN( ll , A );
    auto itr = C.begin();
    FOR_LL( j , 1 , A ){
      itr++;
    }
    C.push_front( *itr );
    C.erase( itr );
  }
  RETURN( ll , C.front() );

}