#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}());
const ll mod=1000000007;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head

const int N = 100010;

int a[N], b[N], k[1010], p[1010];
ll f[11][1010];

int main() {
    int n, m;
    while(scanf("%d%d", &n, &m)==2) {
        for(int i=1; i<=n; i++)
            scanf("%d%d", &a[i], &b[i]);
        for(int i=1; i<=m; i++)
            scanf("%d%d", &k[i], &p[i]);
        for(int d=0; d<=10; d++) {
            for(int h=1; h<=1000; h++) {
                f[d][h] = 1e18;
                for(int i=1; i<=m; i++) {
                    if(p[i]<=d)
                        continue;
                    f[d][h] = min(f[d][h], f[d][max(h-p[i]+d, 0)]+k[i]);
                }
            }
        }
        ll ans = 0;
        for(int i=1; i<=n; i++) {
            if(f[b[i]][a[i]]>=1e18) {
                ans = -1;
                break;
            }
            ans += f[b[i]][a[i]];
        }
        printf("%lld\n", ans);
    }
    return 0;
}