#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <cmath>
#include <ctime>
#include <vector>
#include <map>
#include <set>
#include <list>
#include <queue>
#include <stack>
#include <string>
#include <sstream>
#include <utility>
#include <iomanip>
#include <algorithm>
using namespace std;

typedef long long LL;
typedef long double LD;
typedef vector<int> VI;
typedef pair<int,int> PII;

const LD eps=1e-9;
const LD PI=atan2((LD)0,(LD)-1);
const LL MOD=1000000007;
const int INF=1<<30;
const int ARR_INF=1<<6;
const int MAXN=100005;
const int MAXM=1005;

int n, m;
int a[MAXN], b[MAXN];
int k[MAXM], p[MAXM];
int dmg[MAXM];
int dp[2*MAXM][11];

void get_dmg()
{
    memset(dmg, -1, sizeof(dmg));
    for(int i=0; i<m; i++) {
        if(dmg[p[i]] == -1 || dmg[p[i]] > k[i])
            dmg[p[i]] = k[i];
    }
    m = 0;
    for(int i=0; i<MAXM; i++) {
        if(dmg[i]!=-1) {
            k[m] = dmg[i];
            p[m++] = i;
        }
    }
}

void solve()
{
    for(int j=0; j<11; j++) {
        dp[0][j] = 0;
        for(int i=1; i<2*MAXM; i++) {
            int min_k = -1;
            if(i+j<MAXM)
                min_k = dmg[i+j];
            for(int l=0; l<m; l++) {
                int dm = p[l] - j;
                if(dm <= 0)
                    continue;
                if(i-dm < 0)
                    break;
                if(dp[i-dm][j] != -1 && (min_k == -1 || min_k > dp[i-dm][j] + k[l]))
                    min_k = dp[i-dm][j] + k[l];
            }
            dp[i][j] = min_k;
        }
        int set_k = dp[2*MAXM-1][j];
        for(int i=2*MAXM-2; i>=0; i--) {
            if(set_k == -1)
                set_k = dp[i][j];
            else {
                if(dp[i][j] != -1)
                    set_k = min(dp[i][j], set_k);
            }
            dp[i][j] = set_k;
        }
    }
}

LL cal_ans()
{
    LL ans = 0;
    for(int i=0; i<n; i++) {
        if(dp[a[i]][b[i]] == -1)
            return -1;
        ans += dp[a[i]][b[i]];
    }
    return ans;
}

int main()
{
    while(scanf("%d%d",&n, &m)!=EOF)
    {
        for(int i=0; i<n; i++)
            scanf("%d%d", a+i, b+i);
        for(int i=0; i<m; i++)
            scanf("%d%d", k+i, p+i);
        get_dmg();
        solve();
        cout<<cal_ans()<<endl;
    }
    return 0;
}