#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cstring>
#include <set>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cctype>
#include <cmath>
#include <stack>
#include <sstream>
#define debug() puts("++++");
#define gcd(a, b) __gcd(a, b)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define freopenr freopen("in.txt", "r", stdin)
#define freopenw freopen("out.txt", "w", stdout)
using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> P;
const int INF = 0x3f3f3f3f;
const LL LNF = 1e16;
const double inf = 0x3f3f3f3f3f3f;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int maxn = 1e5 + 10;
const int mod = 1e9 + 7;
const int dr[] = {-1, 0, 1, 0};
const int dc[] = {0, 1, 0, -1};
const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
int n, m;
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
inline bool is_in(int r, int c){
  return r >= 0 && r < n && c >= 0 && c < m;
}

int dp[1005][12];
int a[maxn], b[maxn];
struct Node{
  int k, p;
  Node(){ }
  Node(int kk, int pp) : k(kk), p(pp) { }
  bool operator < (const Node &rhs) const{
    return p < rhs.p;
  }
};
Node c[1005];

int main(){
  while(scanf("%d %d", &n, &m) == 2){
    int t = 0, tt = 0;
    for(int i = 0; i < n; ++i){
      scanf("%d %d", a+i, b+i);
      t = max(t, b[i]);
      tt = max(tt, a[i]);
    }
    for(int j = 0; j < m; ++j)  scanf("%d %d", &c[j].k, &c[j].p);
    sort(c, c + m);
    if(c[m-1].p <= t){
      printf("-1\n");  continue;
    }
//    int v;
//    while(cin >> v){
//      printf("%d\n", upper_bound(c, c + m, Node(0, v)) - c);
//    }
//    for(int j = )
    memset(dp, INF, sizeof dp);
    for(int k = 0; k <= t; ++k){
      dp[0][k] = 0;
      int pp = upper_bound(c, c + m, Node(-1, k)) - c;
      for(int i = pp; i < m; ++i){
        for(int j = 1; j <= tt; ++j)
          dp[j][k] = min(dp[j][k], dp[max(0, j-c[i].p+k)][k] + c[i].k);
      }
    }
    LL ans = 0;
    for(int i = 0; i < n; ++i)
      ans += dp[a[i]][b[i]];
    printf("%I64d\n", ans);
  }
  return 0;
}