#include <bits/stdc++.h>
using namespace std;
const long long inf = 1LL << 55;
long long times(long long a, long long b) {
  if (inf / b < a)
    return inf;
  else
    return a * b;
}
int main() {
  long long N, M;
  cin >> N >> M;
  long long A[N], B[M];
  long long sumA = 0, sumB = 0;
  for (int i = 0; i < N; i++) {
    cin >> A[i];
    sumA += A[i];
  }
  for (int i = 0; i < M; i++) {
    cin >> B[i];
    sumB += B[i];
  }
  sort(A, A + N);
  sort(B, B + M);
  long long best = times(N, sumB);
  long long sum = 0;
  for (long long i = 0; i < N - 1; i++) {
    best = min(best, sum + times(sumB, (N - i)));
    sum += A[i];
  }
  best = min(best, sum + times(sumB, 1));
  best = min(best, times(M, sumA));
  sum = 0;
  for (long long i = 0; i < M - 1; i++) {
    best = min(best, sum + times((sumA), (M - i)));
    sum += B[i];
  }
  best = min(best, sum + times(sumA, 1));
  cout << best << endl;
  return 0;
}
