#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <complex>
#include <cassert>
#define LL long long
using namespace std;
const int M = 1e3 + 5, mod = 1e9 + 7, MOD = 1e9 + 7;
const LL INF = 1e18;
const double PI = acos(-1);
vector<int>B[11];
struct node {
    int k, p;
    void read() {
        scanf("%d%d", &k, &p);
    }
} A[M];
int main() {
    int n, m;
    while(scanf("%d%d", &n, &m) != EOF) {
        for(int j = 0; j <= 10; j++) B[j].clear();
        for(int j = 1; j <= n; j++) {
            int a, b;
            scanf("%d%d", &a, &b);
            B[b].push_back(a);
        }
        for(int j = 1; j <= m; j++) {
            A[j].read();
        }
        LL ans = 0;
        int ok = 1;
        for(int j = 0; j <= 10; j++) {
            if(!B[j].size()) continue;
            int maxx = 0;
            for(auto x : B[j]) {
                maxx = max(maxx, x);
            }
            vector<LL>dp(maxx + 1, INF);
            dp[0] = 0;
            for(int k = 1; k <= m; k++) {
                if(A[k].p <= j) continue;
                for(int i = 0; i <= maxx; i++) {
                    dp[min(maxx, i + A[k].p - j)] = min(dp[min(maxx, i + A[k].p - j)], dp[i] + A[k].k);
                }
            }
            for(int i = maxx - 1; i >= 0; i--) {
                dp[i] = min(dp[i], dp[i + 1]);
            }
            for(auto x : B[j]) {
                if(dp[x] == INF) ok = 0;
                ans += dp[x];
            }
        }
        if(!ok) ans = -1;
        printf("%I64d\n", ans);
    }
    return 0;
}