#include <bits/stdc++.h>
#define ll long long

using namespace std;

ll memo[110][100010];

const ll INF = 1e11+10;

int v[110], w[110];
int N, W;


ll dp(int i, int cap){
    if(cap < 0) return -INF;
    if(i == N) return 0;

    if(memo[i][cap] != -1) return memo[i][cap];

    return memo[i][cap] = max(dp(i+1,cap-w[i])+v[i], dp(i+1,cap));
}

int main(){
    scanf("%d %d", &N, &W);

    memset(memo, -1, sizeof memo);

    for(int i = 0; i < N; i++){
        scanf("%d %d", &w[i], &v[i]);
    }

    printf("%lld", dp(0,W));

}