#include<bits/stdc++.h> using namespace std; int n,m; int a[50005],b[50005],sum; int main() { freopen("toy.in","r",stdin); freopen("toy.out","w",stdout); cin>>n>>m; for(int i=1;i<=n;i++) { cin>>a[i]; } for(int i=1;i<=m;i++) { cin>>b[i]; } sort(a+1,a+n+1); sort(b+1,b+m+1); long long i=1,j=1; while(i<=n&&j<=m) { if(a[i]<=b[j]) { sum+=b[j]; i++,j++; } else { j++; } } if(i<=n) { cout<<-1; } else { cout<<sum; } return 0; }