#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

const int maximumVolume = 1000 + 10, maximumNumber = 1000 + 10;

int totalNumber, totalVolume;

void initialization(){
    scanf("%d%d", &totalNumber, &totalVolume);
}

int maximumValueRecord[maximumVolume];//不是正方形表

int currentVolume, currentValue;

void recurrence(){
    for (int rank = 0; rank < totalNumber; rank ++){
        scanf("%d%d", &currentVolume, &currentValue);
        for (int volume = totalVolume; volume >= currentVolume; volume --){
            int referenceValueFirst = maximumValueRecord[volume];
            int referenceValueSecond = maximumValueRecord[volume - currentVolume] + currentValue;
            maximumValueRecord[volume] = max(referenceValueFirst, referenceValueSecond);
        }
    }
}

void outputMaximumResult(){
    printf("%d", maximumValueRecord[totalVolume]);
}

int main(){
    initialization();
    recurrence();
    outputMaximumResult();
    return 0;
}