#include<cstdio>#include<cstring>#include<queue>#include<algorithm>#include<set>using namespace std;#define NN 101000struct node{ int a,b; bool operator <(const node &y)const{ return b>y.b; }}a[NN],w[NN],tn;bool cmp(const node &a,const node &b){ return a.a<b.a;}int main(){ int n,m,i,tot,p; scanf("%d%d",&n,&m); for(i=1;i<=n;++i){ scanf("%d%d",&a[i].a,&a[i].b); } for(i=1;i<=m;++i){ scanf("%d%d",&w[i].a,&w[i].b); } multiset<node> st; multiset<node>::iterator it; sort(a+1,a+n+1,cmp); sort(w+1,w+m+1,cmp); tot=0; p=1; long long ans=0; for(i=1;i<=m;++i){ while (p<=n&&a[p].a<=w[i].a) {st.insert(a[p]);++p;} it=st.lower_bound(w[i]); if (it!=st.end()) { st.erase(it); tot++; ans+=w[i].a; } if (tot==n) break; } if (tot==n) printf("%I64dn",ans); else printf("-1n"); return 0;}
