!7

p {
  int n = 10000000;
  S a = rep(n, 'a') + rep(n, 'b');
  S b = rep(n+10, 'a') + rep(n-10, 'b');
  for (int max = 0; max <= 20; max++)
    time { print("max " + max + " => " + leven_limited(a, b, max)); }
}