#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)

void solve(){
    
}

int main(){

    ll n, V, c; cin >> n >> V >> c;
    vll v(n), w(n); rep(i, n) cin >> v[i] >> w[i];
    vvll dp(n, vll(V+1, 0));
    for(ll i = 1; i*v[0] <= V; i += v[0])dp[0][i*v[0]] = w[0]*i + c;
    rep2(i, 1, n){
        rep(j, V+1)dp[i][j] = dp[i-1][j];
        rep(j, V+1){
            if(j - v[i] < 0)continue;
            dp[i][j] = max({dp[i][j], dp[i-1][j-v[i]] + w[i] + c, dp[i][j-v[i]] + w[i]});
        }
    }
    ll ans = 0;
    rep(i, V+1)ans = max(ans, dp[n-1][i]);
    cout << ans << endl;
       
    return 0;
}