func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX = 200020;   const long long MOD = (int)1e9 + 7;   const int INF = 1e9;   const long long LLINF = 0x3f3f3f3f3f3f3f3f;   const long double EPS = 1e-7;   void get_sub(string s, int size, set<string>& sub) {     int n = s.size();     for (int l = 0, r = size - 1; r < n; l++, r++) {       string t = s.substr(l, size);       sub.insert(t);     }   }   set<string> merge(set<string> a, set<string> b) {     set<string> res = a;     for (auto s : b) {       res.insert(s);     }     return res;   }   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     ;     int n, m;     cin >> n;     vector<string> pre(301, string()), suf(301, string());     vector<vector<set<string>>> sub(301, vector<set<string>>(10, set<string>()));     for (int i = 1; i <= n; i++) {       string s;       cin >> s;       int sz = s.size();       pre[i] = s.substr(0, min(9, sz));       suf[i] = s.substr(max(0, sz - 9), min(9, sz));       for (int k = 1; k <= 9; k++) {         get_sub(s, k, sub[i][k]);       }     }     cin >> m;     for (int i = 1; i <= m; i++) {       int a, b;       cin >> a >> b;       string t = suf[a] + pre[b];       int sz = t.size();       string p = pre[a] + pre[b];       sz = p.size();       pre[n + i] = p.substr(0, min(9, sz));       string s = suf[a] + suf[b];       sz = s.size();       suf[n + i] = s.substr(max(0, sz - 9), min(9, sz));       for (int k = 1; k <= 9; k++) {         sub[n + i][k] = merge(sub[a][k], sub[b][k]);         get_sub(t, k, sub[n + i][k]);       }       int res = 0;       for (int k = 1; k <= 9; k++) {         if ((int)sub[n + i][k].size() == (1 << k)) res = k;       }       cout << res <<   n ;     }     return 0;   }   