ВерсутаСынСобаки

#include <bits/stdc++.h>

using namespace std;

int main()
{
 //   freopen("input.txt", "r", stdin);
    int g[32];
    int suf[32];
    int n, m;
    cin >> n >> m;

    for(int i = 1; i <= n; ++i)
    {
        g[i] = (1 << i);
    }

    for(int i = 0; i < m; ++i)
    {
        int a, b;
        cin >> a >> b;
        g[a] |= (1 << b);
        g[b] |= (1 << a);
    }

    suf[n + 1] = 0;
    for(int i = n; i > 0; --i)
    {
        suf[i] = suf[i + 1] | g[i];
    }

    int nm[32];
    int cur[32];

    int ptr = 1;
    nm[ptr] = 1;
    cur[0] = 0;
    cur[ptr] = 0;

    int ans = 0;
    int np1 = n + 1;
    int msk = (1 << (n + 1)) - 2;

    versuta:
    if(ptr == 0)
    {
        cout << ans << endl;
        return 0;
    }
    if(cur[ptr] == msk)
    {
        ans += (1 << (n + 1 - ptr));
        --ptr;
        goto versuta;
    }
    if(ptr == np1)
    {
        --ptr;
        goto versuta;
    }
    if(nm[ptr] == -1)
    {
        --ptr;
        goto versuta;
    }
    if((cur[ptr] | suf[ptr]) != msk)
    {
        --ptr;
        goto versuta;
    }
    if(nm[ptr] == 0)
    {
        cur[ptr + 1] = cur[ptr];
        nm[ptr] = -1;
        ++ptr;
        nm[ptr] = 1;
        goto versuta;
    }
    if(nm[ptr] == 1)
    {
        cur[ptr + 1] = g[ptr] | cur[ptr];
        nm[ptr] = 0;
        ++ptr;
        nm[ptr] = 1;
        goto versuta;
    }
}