#include <iostream>
#include <fstream>

using namespace std ;

const int NR = 5005 ;

ifstream f ("energii.in") ;
ofstream g ("energii.out") ;

long long t [ 2 ][ NR ] ;

int main ()
{
    int n , k ; f >> n >> k ;
    
    while ( n -- )
    {
        int x , y ; f >> x >> y ;
        
        for ( int i = 1 ; i <= k ; ++ i )
        {
            if ( i < x )    t [ n % 2 ][ i ] = t [ ( n + 1 ) % 2 ][ i ] ;
            else
            t [ n % 2 ][ i ] = max ( t [ ( n + 1 ) % 2 ][ i ] , t [ ( n + 1 ) % 2 ][ i - x ] + y ) ;
        }
        
    }
    
    g << t [ 0 ][ k ] << "\n" ;
    
    
    return 0 ;
}