#include <iostream>
#include<ctime>
#include<map>
#include<vector>
#include<queue>
using namespace std;
int n;
int values[2002], weights[2002];
int maximum_weight;
int dp[2002][3502];
int rec(int i, int weight_left) {
    if(i == n or weight_left == 0) {
        return 0;
    }
    if(dp[i][weight_left] != -1) {
        return dp[i][weight_left];
    }
    int result = 0;
    result = max(result, rec(i + 1, weight_left));
    if(weight_left - weights[i] >= 0) {
        result = max(result, rec(i + 1, weight_left - weights[i]) + values[i]);
    }
    dp[i][weight_left] = result;
    return result;
}
int main()
{
    cin >> n;
    for(int i = 0; i < n; i++) {
        cin >> values[i];
        cin >> weights[i];
    }
    cin >> maximum_weight;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j <= maximum_weight; j++) {
            dp[i][j] = -1;
        }
    }
    cout << rec(0, maximum_weight) << endl;
    return 0;
}