import std.algorithm, std.array, std.container, std.range, std.bitmanip;
import std.numeric, std.math, std.bigint, std.random, core.bitop;
import std.string, std.conv, std.stdio, std.typecons;

void main()
{
  auto t = readln.chomp.to!int;
  auto n = readln.chomp.to!int;
  auto ci = readln.split.map!(to!int).array;
  auto vi = readln.split.map!(to!int).array;

  auto memo = new int[](t + 1);
  memo[0] = 0;
  memo[1..$] = -1;

  foreach (i; 0..n) {
    auto memo2 = new int[](t + 1);
    memo2[] = -1;

    auto dvi = calcDvi(vi[i]);
    foreach (j; ci[i]..t + 1) {
      if (memo[j - ci[i]] >= 0) {
        foreach (k, dv; dvi) {
          auto m = j + k * ci[i];
          if (m <= t) {
            if (memo2[m] >= 0)
              memo2[m] = max(memo[j - ci[i]], dv);
            else
              memo2[m] = memo[j - ci[i]] + dv;
          }
        }
      }
    }
    foreach (j; 0..t + 1) {
      if (memo2[j] >= 0) {
        if (memo[j] >= 0)
          memo[j] = max(memo[j], memo2[j]);
        else
          memo[j] = memo2[j];
      }
    }
  }

  writeln(memo.reduce!(max));
}

int[] calcDvi(int v)
{
  int[] dvi;
  for (auto c = v; v > 0; v /= 2, c+= v)
    dvi ~= c;
  return dvi;
}