#include <iostream>     // Input/output stream objects
#include <fstream>      // File stream objects
#include <sstream>      // String stream objects
#include <iomanip>      // Input/output manipulators
#include <string>       // String class and functions
#include <vector>       // Dynamic array
#include <list>         // Doubly linked list
#include <set>          // Set container
#include <map>          // Map container
#include <queue>        // Queue container
#include <stack>        // Stack container
#include <algorithm>    // Algorithms on sequences (e.g., sort, find)
#include <cmath>        // Mathematical functions
#include <ctime>        // Date and time functions
#include <cstdlib>      // General purpose functions (e.g., memory management)
#include <cstring>      // C-style string functions
#include <cctype>       // Character classification functions
#include <cassert>      // Assert function for debugging
#include <exception>    // Standard exceptions
#include <functional>   // Function objects
#include <iterator>     // Iterator classes
#include <limits>       // Numeric limits
#include <locale>       // Localization and internationalization
#include <numeric>      // Numeric operations (e.g., accumulate)
#include <random>       // Random number generators
#include <stdexcept>    // Standard exception classes
#include <typeinfo>     // Runtime type information
#include <utility>      // Utility components (e.g., std::pair)
#include <bitset>

using namespace std;

#define FOR(i, a, b) for(int i = a; i < (b); i++)
#define FORE(i, a, b) for(int i = a; i <= (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
#define x first 
#define y second
#define mp make_pair
#define PI 3.141592653
const double eps = 1e-9;

const int N = 3e5;
const ll mod = 1e9 + 7;
int m, n;
vector<ll> num(N);

ll solve(int l, int r) {
    if (l == r) return 1;
    int mid = l + r >> 1;
    bool chk = true;

    FORE (i, l, mid) if (num[i] != num[i+(r-l+1)/2]) {
        chk = false;
        break ;
    }

    if (chk) return (2LL * solve(l, mid)) % mod;
    else {
        set<int> left;
        FORE (i, l, mid) left.insert(num[i]);
        FORE (i, mid + 1, r) if (left.find(num[i]) != left.end()) return 0;
        return (solve(l, mid) * solve(mid + 1, r)) % mod;
    }
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
    cin >> m >> n;

    vector<int> cnt(n+5, 0);
    FORE (i, 1, (1 << m)) {
        cin >> num[i];
        cnt[num[i]] = 1;
    }
    FORE (i, 1, n) if (cnt[i] == 0) {
        cout << "0" << endl;
        return 0;
    }
    cout << solve(1, (1 << m)) << endl;
    return 0;
}