#include <cstdio>
#include <cstring>
#include <algorithm>
#define x first
#define y second
using namespace std;
typedef pair<int, int> PII;
typedef long long LL;
const int N = 500010;
int n, m;
PII a[N], b[N];
int main()
{
    scanf("%*d%d%d", &n, &m);
    for (int i = 0; i < n; i ++ ) scanf("%d%d", &a[i].x, &a[i].y);
    for (int i = 0; i < m; i ++ ) scanf("%d%d", &b[i].x, &b[i].y);
    LL res = 0;
    for (int i = 0, j = 0; i < n && j < m; i ++ )
    {
        while (j < m && b[j].x < a[i].x) j ++ ;
        if (j < m && b[j].x == a[i].x) res += (LL)a[i].y * b[j].y;
    }
    printf("%lld\n", res);
    return 0;
}