func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5e5 + 7;   const int MX = 1e9 + 7;   const long long int INF = 1e18 + 9LL;   int n, m, k;   long long int value[N];   pair<long long int, pair<int, int> > edge[N];   int pt[N];   int rep[N];   int res = 0;   int Find(int a) {     if (rep[a] == a) return a;     return rep[a] = Find(rep[a]);   }   bool Union(int a, int b) {     a = Find(a), b = Find(b);     if (a == b) return false;     rep[a] = b;     return true;   }   void solve(int from, int to) {     int cnt = n;     for (int i = from; i <= to; ++i)       if (Union(edge[i].second.first, edge[i].second.second)) --cnt;     res = (res + pt[cnt]) % MX;     for (int i = from; i <= to; ++i)       rep[edge[i].second.first] = edge[i].second.first,       rep[edge[i].second.second] = edge[i].second.second;   }   int main() {     scanf( %d %d %d , &n, &m, &k);     for (int i = 1; i <= n; ++i) {       scanf( %lld , &value[i]);       rep[i] = i;     }     pt[0] = 1;     for (int i = 1; i < N; ++i) pt[i] = (pt[i - 1] + pt[i - 1]) % MX;     for (int i = 1; i <= m; ++i) {       int u, v;       scanf( %d %d , &u, &v);       edge[i] = {value[u] ^ value[v], {u, v}};     }     long long int ok = pt[k];     sort(edge + 1, edge + m + 1);     for (int i = 1; i <= m; ++i) {       int t = i;       while (t < m && edge[t + 1].first == edge[t].first) ++t;       solve(i, t);       i = t;       --ok;     }     res = (res + 1LL * pt[n] * (ok % MX)) % MX;     printf( %d n , res);     return 0;   }   