#include <bits/stdc++.h>
using namespace std;

#define all(x) begin(x), end(x)
#ifdef CKISEKI
#define safe cerr << __PRETTY_FUNCTION__ << " line " << __LINE__ << " safe\n"
#define debug(a...) debug_(#a, a)
#define orange(a...) orange_(#a, a)
void debug_(const char *s, auto ...a) {
  cerr << "\e[1;32m(" << s << ") = (";
  int f = 0;
  (..., (cerr << (f++ ? ", " : "") << a));
  cerr << ")\e[0m\n";
}
void orange_(const char *s, auto L, auto R) {
  cerr << "\e[1;32m[ " << s << " ] = [ ";
  for (int f = 0; L != R; ++f)
    cerr << (f ? ", " : "") << *L++;
  cerr << " ]\e[0m\n";
}
#else
#define safe ((void)0)
#define debug(...) safe
#define orange(...) safe
#endif

const int maxn = 100025 * 60;
const int inf = 1e9;
int ch[maxn][2];
int cnt[maxn];
int dp[maxn][2];
int tot;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);

  int64_t n;
  int m;
  cin >> n >> m;

  const int l = __lg(n);
  const auto F = [&](int64_t p) {
    for (int i = l - 1; i >= 1; i--) {
      if (p >> i & 1) {
        int64_t z = p >> i;
        p = (z << i) + ((z + 1) << i) - 1 - p;
      }
    }
    int64_t q = 0;
    for (int j = 0; j < l; j++) {
      q <<= 1;
      q |= p & 1;
      p >>= 1;
    }
    return q;
  };

  const auto Insert = [&](int64_t z) {
    int now = 0;
    for (int j = l - 1; j >= 0; j--) {
      int d = z >> j & 1;
      if (!ch[now][d]) {
        ch[now][d] = ++tot;
      }
      now = ch[now][d];
      ++cnt[now];
    }
  };

  const auto Dp = [&]() {
    const auto dfs = [&](auto self, int i) {
      const int now = i;
      debug(i, cnt[i]);
      if (!ch[now][0] && !ch[now][1]) {
        dp[i][0] = cnt[i] != 0;
        dp[i][1] = cnt[i] == 0;
        return;
      }

      if (ch[now][0]) {
        self(self, ch[now][0]);
        dp[i][0] += dp[ch[now][0]][0];
        dp[i][1] += dp[ch[now][0]][1];
      } else {
        dp[i][1] = inf;
      }

      if (ch[now][1]) {
        self(self, ch[now][1]);
        dp[i][0] += dp[ch[now][1]][0];
        dp[i][1] += dp[ch[now][1]][1];
      } else {
        dp[i][1] = inf;
      }

      dp[i][0] = min(dp[i][0], dp[i][1] + 1);
      dp[i][1] = min(dp[i][1], dp[i][0] + 1);

    };

    dfs(dfs, 0);
    return min(dp[0][0], dp[0][1]);
  };

  for (int i = 0; i < m; i++) {
    int64_t x;
    cin >> x;
    --x;
    x = F(x);
    debug(x);
    Insert(x);
  }

  cout << Dp() << '\n';

  return 0;
}