#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

typedef long long LL;

const int N = 200010;

int n, m;
LL S;
int w[N], v[N];
int l[N], r[N];
int cnt[N];
LL sum[N];

LL get(int W)
{
    for (int i = 1; i <= n; i ++ )
        if (w[i] >= W)
        {
            sum[i] = sum[i - 1] + v[i];
            cnt[i] = cnt[i - 1] + 1;
        }
        else
        {
            sum[i] = sum[i - 1];
            cnt[i] = cnt[i - 1];
        }

    LL res = 0;
    for (int i = 0; i < m; i ++ ) res += (cnt[r[i]] - cnt[l[i] - 1]) * (sum[r[i]] - sum[l[i] - 1]);
    return res;
}

int main()
{
    scanf("%d%d%lld", &n, &m, &S);
    for (int i = 1; i <= n; i ++ ) scanf("%d%d", &w[i], &v[i]);
    for (int i = 0; i < m; i ++ ) scanf("%d%d", &l[i], &r[i]);

    int l = 0, r = 1e6 + 1;
    while (l < r)
    {
        int mid = l + r + 1 >> 1;
        if (get(mid) >= S) l = mid;
        else r = mid - 1;
    }

    printf("%lld\n", min(abs(get(r) - S), abs(S - get(r + 1))));

    return 0;
}