#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;
#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<int,int> 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 eps=1e-8;
const int inf=0x3f3f3f3f;
 ll mod=1e9+7;
const int maxn=1e5+50;
/*======================================*/
struct node{
    ll k,p;
    void in(){
        RD(k),RD(p);
    }
    bool operator<(const node &t)const{
        if(p!=t.p)return p<t.p;
        return k>t.k;
    }
}e[maxn],a[maxn];
ll dp[1000+50];
int main(){
    int n,m;
    while(~scanf("%d%d",&n,&m)){
        ll ans=0;
        int fl=0;
        REP(i,n)a[i].in();
        REP(i,m)e[i].in();
        sort(a,a+n);
        sort(e,e+m);
        REP(i,n){
            int lim=(int)a[i].k;
            if(i&&a[i].p==a[i-1].p)
                goto lab;
            mem(dp,-1);
            dp[0]=0;
            for(int j=m-1;j>=0;j--){
                int w=(int)(e[j].p-a[i].p);
                //OT(w),pe();
                if(w<=0)break;
                for(int k1=0;k1<=lim;k1++)if(dp[k1]!=-1){
                    int now=min(k1+w,lim);
                    if(dp[now]==-1)dp[now]=dp[k1]+e[j].k;
                    else dp[now]=min(dp[now],dp[k1]+e[j].k);
                }    
            }
            dp[lim+1]=1e12;
            for(int j=lim;j>=0;j--){
                if(dp[j]==-1)dp[j]=dp[j+1];
                else dp[j]=min(dp[j],dp[j+1]);
                //printf("%I64d ",dp[j]);
            }
           // puts("");
            lab:
            if(dp[lim]!=1e12)ans+=dp[lim];
            else fl=1;
        }
        if(fl)puts("-1");
        else printf("%I64d\n",ans);
    }
    return 0;
}