View Compilation Error

0_0_17379417_30374.cpp: In function 'int FindFather(int)':
0_0_17379417_30374.cpp:16:8: error: 'city' was not declared in this scope
     if(city[x] == x) return x;
        ^
0_0_17379417_30374.cpp:17:12: error: 'city' was not declared in this scope
     return city[x] = FindFather(city[x]);
            ^
0_0_17379417_30374.cpp: In function 'int Link(int, int)':
0_0_17379417_30374.cpp:26:9: error: 'city' was not declared in this scope
         city[Fa] = Fb;
         ^
0_0_17379417_30374.cpp:29:5: error: 'city' was not declared in this scope
     city[Fb] = Fa;
     ^