#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <string>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#define k first
#define p second
#define clr(u,v); memset(u,v,sizeof(u));
#define in() freopen("data","r",stdin);
#define out() freopen("ans","w",stdout);
#define Clear(Q); while (!Q.empty()) Q.pop();
#define pb push_back
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int maxn = 1e5 + 10;
const ll INF = 1e17;
struct node
{
    int a, b;
    bool operator < (const node &A) const
    {
        if (b != A.b)
            return b < A.b;
        return a > A.a;
    }
} N[maxn];
ll dp[2010];
pii M[1010];
int main()
{
#ifdef LOCAL
    in();
#endif
    int n, m;
    while (~scanf("%d%d", &n, &m))
    {
        for (int i = 0; i < n; i++)
        {
            scanf("%d%d", &N[i].a, &N[i].b);
        }
        for (int i = 0; i < m; i++)
        {
            scanf("%d%d", &M[i].k, &M[i].p);
        }
        sort(N, N + n);
        int pos = 0;
        ll ans = 0;
        int ok =  1;
        for (int b = 0; b <= 10 && ok; b++)
        {
            for (int i = 0; i <= 2000; i++) dp[i] = INF;
            dp[0] = 0;
            for (int i = 0; i < m; i++)
            {
                int x = max(0, M[i].p - b);
                for (int j = 0; j <= 2000; j++)
                    dp[j] = min(dp[j], dp[j-x] + M[i].k);
            }
            int st = 2000;
            ll Min = INF;
            while (pos < n && N[pos].b <= b)
            {
                while (st >=0 && st >= N[pos].a)
                {
                    Min = min(Min, dp[st]);
                    st--;
                }
                pos++;
                if (Min == INF)
                {
                    ok=0;
                    break;
                }
                ans += Min;
            }
        }
        if (ok==0) ans=-1;
        printf("%I64d\n", ans);
    }
    return 0;
}