func_code_string: #include <bits/stdc++.h>   using namespace std;   struct M {     int x, y, z;   };   int dis(int x, int y) { return abs(x - y); }   signed main() {     ios::sync_with_stdio(0);     cin.tie(0);     ;     int n;     cin >> n;     M note[5000];     vector<bool> vs(5000, 0);     for (int i = 1; i <= n; i++) {       cin >> note[i].x >> note[i].y >> note[i].z;     }     for (int i = 1; i <= n; i++) {       int X = INT_MAX, Y = INT_MAX, Z = INT_MAX, now;       if (!vs[i]) {         for (int j = 1; j <= n; j++) {           if (i != j && !vs[j]) {             int disX = dis(note[i].x, note[j].x);             int disY = dis(note[i].y, note[j].y);             int disZ = dis(note[i].z, note[j].z);             if (disX < X) {               now = j;             } else if (disX == X) {               if (disY < Y)                 now = j;               else if (disY == Y) {                 if (disZ < Z) now = j;               }             }             if (now == j) {               X = disX;               Y = disY;               Z = disZ;             }           }         }         cout << i <<     << now << endl;         vs[i] = 1;         vs[now] = 1;       }     }   }   