#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<stack>
#include<queue>
using namespace std;
#pragma comment(linker, "/STACK:10240000000,10240000000")
#define mem(x,y) memset(x,y,sizeof(x))
#define pb push_back
#define bug puts("===========");
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define ALL(A) A.begin(), A.end()
#define T_T for(int _=RD(),test=1;test<=_;test++)
typedef long long ll;
typedef pair<ll ,ll> pii;
#define CHG ch=getchar()
#define FRD x=bo=0; for(CHG;ch<'0'||ch>'9';CHG) if(ch=='-')bo=1;
#define FR2 for(;ch>='0'&&ch<='9';x=(x<<1)+(x<<3)+ch-'0',CHG);
char ch; int bo;
inline bool blank(char ch){return ch==' '||ch=='\n'||ch=='\r'||ch=='\t';}
inline void RD(int &x){ FRD FR2 if (bo)x=-x; }
inline void RD(ll &x){ FRD FR2 if (bo)x=-x; }
inline ll RD(){ ll x; RD(x); return x; }
inline void RD(char *s){///scanf %s
    for (CHG;blank(ch);CHG);
    for (;!blank(ch);CHG)*s++=ch; *s=0;
}
inline void RD(char &c){for(CHG;blank(c);CHG);}
template<class T> inline void OT(T x){
    static char buf[20];
    char *p1=buf;if (!x)*p1++='0';if (x<0)putchar('-'),x=-x;
    while(x)*p1++=x%10+'0',x/=10;
    while(p1--!=buf)putchar(*p1);
}
inline void pe(){puts("");}//输出回车
inline void pk(){putchar(' ');}//输出空格
const double inf=1e9;
const ll mod =100000007;
const long long INF =2e18+5;
#define pii pair<ll,point>
#define mytype ll
const int maxn=1e5+3;
/*======================================*/
ll dp[12][2008];
ll a[maxn],b[maxn],kk[maxn],p[maxn];
int main(){
    int n,m;
    while(~scanf("%d",&n)){
        RD(m);
        REP(i,n) {
            RD(a[i]); RD(b[i]);
        }
        REP(i,m) {
            RD(kk[i]); RD(p[i]);
        }
        REP(i,11){
            REP(k,2005) dp[i][k]=1e10;
            dp[i][0]=0;
            REP(j,m)if(p[j]>i){
                int attack=p[j]-i;
                for(int k=attack;k<2005;k++){
                    dp[i][k]=min(dp[i][k],dp[i][k-attack]+kk[j]);
                }
            }
            for(int k=2003;k>=0;k--) dp[i][k]=min(dp[i][k],dp[i][k+1]);
        }
        ll ans=0;
        REP(i,n) {
            ans+=dp[b[i]][a[i]];
            if(dp[b[i]][a[i]]==1e10) {
                ans=-1; break;
            }
        }
        OT(ans); pe();
    }

    return 0;
}