func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(void) {     int n, m;     cin >> n >> m;     vector<vector<int> > file(n);     for (int i = (0); i < ((m)); ++i) {       int tmp;       cin >> tmp;       vector<int> f(tmp);       for (int j = (0); j < ((tmp)); ++j) cin >> f[j];       file.push_back(f);     }     vector<int> v;     for (int i = (0); i < ((file.size())); ++i)       for (int j = (0); j < ((file[i].size())); ++j) v.push_back(file[i][j]);     sort((v).begin(), (v).end());     int emp = v.size() + 1;     for (int i = (0); i < ((v.size())); ++i) {       if (i + 1 != v[i]) {         emp = i + 1;         break;       }     }     int index = 1;     vector<pair<int, int> > res;     for (int i = (0); i < ((file.size())); ++i) {       for (int j = (0); j < ((file[i].size())); ++j) {         for (int k = (0); k < ((file.size())); ++k) {           for (int l = (0); l < ((file[k].size())); ++l) {             if (file[k][l] == index) {               if (i != k || j != l) {                 int tmp;                 res.push_back(make_pair(file[k][l], emp));                 res.push_back(make_pair(file[i][j], index));                 tmp = file[k][l];                 file[k][l] = emp;                 emp = file[i][j];                 file[i][j] = tmp;               }               ++index;               goto NEXT;             }           }         }         res.push_back(make_pair(file[i][j], index));         emp = file[i][j];         file[i][j] = index;         ++index;       NEXT:;       }     }     cout << res.size() << endl;     for (int i = (0); i < ((res.size())); ++i)       cout << res[i].first <<     << res[i].second << endl;   }   