#include <iostream>
#include <stdio.h>
#include <stdint.h>
using namespace std;

using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define FOR_LL( VAR , INITIAL , FINAL_PLUS_ONE ) for( ll VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define RETURN( LL , ANSWER ) const LL answer_for_contest = ( ANSWER ); cout << answer_for_contest << endl; return 0 

int main()
{

  // X ^ K
  // = sum( ll i = 0 ; true ; i++ ) A( i ) Combination( X , i )
  // = sum( ll i = 0 ; i <= k ; i++ ) A( i ) Combination( X , i )
  // A( I ) = Difference ^ I( X ^ K )( 0 )
  // = sum( ll i = 0 ; i <= I ; j++ ) ( -1 ) ^ ( I - i ) * Combination( I , i ) * i ^ K
  CIN( ll , K );
  CIN( ll , I );
  if( K < I ){
    RETURN( ll , 0 );
  }
  ll I_next = I + 1;
  ll answer = 0;
  ll combination = 1;
  FOR_LL( i , 0 , I_next ){
    ll exponent = K;
    ll power = 1;
    ll power2 = i;
    while( exponent != 0 ){
      if( exponent % 2 == 1 ){
	power *= power2;
      }
      exponent /= 2;
      power2 = power2 * power2;
    }
    answer += ( ( I - i ) % 2 == 0 ? 1 : -1 ) * combination * power;
    combination = ( combination * ( I - i ) ) / ( i + 1 );
  }
  RETURN( ll , answer );

}