import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.format;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;

alias sread = () => readln.chomp();
alias Point2 = Tuple!(long, "y", long, "x");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}

enum MOD = (10 ^^ 9) + 7;

void main()
{
    long N, M;
    scan(N, M);
    bool[8][8] G;
    foreach (_; 0 .. M)
    {
        long a, b;
        scan(a, b);
        G[a - 1][b - 1] = G[b - 1][a - 1] = true;
    }
    // writeln(G);
    auto ary = [1, 2, 3, 4, 5, 6, 7].take(N - 1).array;
    long cnt;
    do
    {
        // writeln(ary);
        bool b = G[0][ary[0]];
        foreach (i; 0 .. N - 2)
            b = b && G[ary[i]][ary[i + 1]];

        cnt += b;
    }
    while (nextPermutation(ary));
    writeln(cnt);
}
