View Compilation Error

0_0_27800970_5104.cpp: In function 'int Find(int)':
0_0_27800970_5104.cpp:3:71: error: 'find' was not declared in this scope
 int Find(int x) { return x == father[x]? x: father[x] = find(father[x]); }
                                                                       ^
0_0_27800970_5104.cpp: In function 'void Combine(int, int)':
0_0_27800970_5104.cpp:4:40: error: 'find' was not declared in this scope
 void Combine(int x, int y) { if (find(x) != find(y)) father[find(x)] = y; }
                                        ^