View Compilation Error

0_0_38585133_11886.cpp: In function 'int main()':
0_0_38585133_11886.cpp:62:29: error: 'G' was not declared in this scope
         for(int i=0;i<n;i++)G[i].clear();
                             ^
0_0_38585133_11886.cpp:68:13: error: 'G' was not declared in this scope
             G[fa].push_back(i);
             ^