#include <bits/stdc++.h>

#define rep(i, j, k) for(int i = (int) j; i < (int) k; ++i)
#define sz(x) ((int) (x).size())
#define ll long long
#define mp make_pair
#define pii pair<int, int >
#define fi first
#define se second
#define pb push_back
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define zero(x) memset((x), (0), sizeof (x))
#define zerox(x, y) memset((x), (y), sizeof (x))

using namespace std;
const int N = 100100;
const int M = 1010;

struct Guai{
    int a, b, t;
    Guai(int a_=0, int b_=0) : a(a_), b(b_) {}
    bool operator<(const Guai& u) const {
        return a < u.a || (a == u.a && b < u.b);
    }
    bool operator==(const Guai& u) const {
        return a == u.a && b == u.b;
    }
} shou[N];

struct Gong{
    int p, k;
    Gong(int p_=0, int k_=0) : p(p_), k(k_) {}
    bool operator < (const Gong& u) const {
        return p > u.p || (p == u.p && k < u.k);
    }
} ji[M];

int n, m;
ll re[M];

int bins(int ps) {
    int l = 0, r = m, mid;
    while(l <= r) {
        mid = (l + r) >> 1;
        if(ji[mid].p <= ps) l = mid + 1;
        else r = mid - 1;
    }
    return l;
}

int main()
{
#ifdef PIT
//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);
#endif //PIT

    // ios_base::sync_with_stdio(false); cin.tie(0);
    while(~scanf("%d %d", &n, &m)) {
        rep(i, 0, n) scanf("%d %d", &shou[i].a, &shou[i].b), shou[i].t = 1;
        sort(shou, shou+n);
        int v = 0;
        rep(i, 1, n) {
            if(shou[v] == shou[i]) shou[v].t++;
            else shou[++v] = shou[i];
        }
        ++v;
        n = v;
        v = 0;
        rep(i, 0, m) scanf("%d %d", &ji[i].k, &ji[i].p);
        sort(ji, ji+m);
        rep(i, 1, m) {
            if(ji[v].k <= ji[i].k) continue;
            else ji[++v] = ji[i];
        }
        ++v;
        m = v;
        reverse(ji, ji+m);

        ji[m] = {inf, inf};
        ll ans = 0LL;
        int f = 1;
        rep(q, 0, n) {
            zerox(re, inf);
            re[shou[q].a] = 0LL;
            int u = bins(shou[q].b);
            if(u >= m) {f = 0; break; }
            for(int i = shou[q].a; i >= 0; --i) if(re[i] != inf){
                for(int j = u; j < m; ++j)  {
                    int x = max(0, i-ji[j].p+shou[q].b);
                    re[x] = min(re[x], re[i]+ji[j].k);
                }
            }
            ans += re[0] * shou[q].t;
        }
        if(!f) puts("-1");
        else printf("%I64d\n", ans);
    }

    return 0;
}