#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <queue>
#include <vector>
#include <stack>
#include <algorithm>
#include <bitset>
#define mem(a,b) memset(a,b,sizeof(a))
#define rep(i,a,n) for(int i=a; i<n; i++)
#define rep1(i,a,n) for(int i=n-1; i>=a; i--)
#define sd(a) scanf("%d",&a)
#define sll(a) scanf("%I64d",&a)
#define test(a) cout<<a<<endl
#define test2(a,b) cout<<a<<" "<<b<<endl
#define IOS ios::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef  long long ll;
const int MAX = 1e6+10;
const int N = 1e4+10;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const ll mod = 1e7+7;
const double pi=3.1415926535898;
const double eps=1e-9;
const int MAXN = 1e4+10;

ll dp[12][MAXN];
int a[MAXN*10];
int b[MAXN*10];
ll k[MAXN];
ll p[MAXN];

void solve()
{
    int n, m;
    while(~sd(n))
    {
        sd(m);
        memset(dp, INF, sizeof(dp));
        for(int i = 0; i < n; ++i)
        {
            sd(a[i]);
            sd(b[i]);
        }
        for(int i = 0; i < m; ++i)
        {
            sll(k[i]);
            sll(p[i]);
        }
        for(int i = 0; i <= 10; ++i)
        {
            dp[i][0] = 0;

            for(int j = 0; j < m; ++j)
            {
                ll x = p[j] - i;
                if(x <= 0) continue;
                for(ll z = 1; z*x <= 1000; z*=2)
                {
                    for(ll l = 1000; l >= 0; --l)
                    {
                        if(l - z*x >= 0)
                            dp[i][l] = min(dp[i][l-z*x] + z*k[j], dp[i][l]);
                        else
                        {
                            dp[i][l] = min(dp[i][l], z*k[j]);
                        }
                    }
                }
            }
        }
        ll ans = 0;
        for(int i = 0; i < n; ++i)
        {
            if(dp[b[i]][a[i]] == INF)
            {
                ans = -1;
                break;
            }
            else{
                ans += dp[b[i]][a[i]];
            }
        }
        printf("%I64d\n", ans);
    }
}


int main()
{
#ifdef local
    freopen("in","r",stdin);
#endif
//    int t;
//    sd(t);
//    while(t--){
    solve();
//    }

    return 0;
}