#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <array>
#include <atcoder/modint>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)

const i64 INF = 1001001001001001001;

using modint = atcoder::static_modint<998244353>;

int main(){
    int N,V,C; cin >> N >> V >> C;
    vector<int> v(N);
    vector<int> w(N);
    rep(i,N) cin >> v[i] >> w[i];

    vector<i64> dp(V+1, 0);
    rep(i,N){
        vector<i64> tmp(V+1, -INF);
        rep(k,V-v[i]+1) tmp[k+v[i]] = dp[k] + C + w[i];
        rep(k,V-v[i]+1) tmp[k+v[i]] = max(tmp[k+v[i]], tmp[k] + w[i]);
        rep(k,V+1) dp[k] = max(dp[k], tmp[k]);
    }

    i64 ans = dp[V];
    cout << ans << '\n';
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;