#include <stdlib.h>
#include <stdio.h>
#include <limits.h>

int compare (const void *a, const void *b)
{  return ( *(int*)a - *(int*)b ); }

int main(void)
{
  FILE *input = fopen("cokolada.in", "r");
  int M, N;
  fscanf(input, "%d", &M);
  fscanf(input, "%d", &N);
  int *rows = malloc(sizeof(int) * (M - 1));
  for (int i = 0; i < M - 1; i++)
    fscanf(input, "%d", &rows[i]);
  int *cols = malloc(sizeof(int) * (N - 1));
  for (int i = 0; i < N - 1; i++)
    fscanf(input, "%d", &cols[i]);
  fclose(input);

  qsort(rows, M-1, sizeof(int), compare);
  qsort(cols, N-1, sizeof(int), compare);
  int rowsI = M - 2;
  int colsI = N - 2;
  int colsCoef = 1;
  int rowsCoef = 1;
  int result = 0;

  // v každém kroku zpracujeme největší ještě nezpracovaný
  // zlom z obou (teď už) setříděných polí
  while (rowsI != -1 || colsI != -1)
  {
    if (rowsI != -1 && 
        (colsI == -1 || rows[rowsI] > cols[colsI])) {
      result += rows[rowsI] * rowsCoef;
      rowsI--;
      colsCoef++;
    } else {
      result += cols[colsI] * colsCoef;
      colsI--;
      rowsCoef++;
    }
  }

  FILE *output = fopen("cena.out", "w");
  fprintf(output, "%d", result);
  fclose(output);
  return 0;
}