View Compilation Error

0_0_22968083_5489.cpp: In function 'void dfs1(int, int)':
0_0_22968083_5489.cpp:40:26: error: 'n' was not declared in this scope
     if(a[u]>son[u]||b[u]>n-son[u]) a[u]=-1;
                          ^
0_0_22968083_5489.cpp: In function 'int main()':
0_0_22968083_5489.cpp:74:21: error: 'n' was not declared in this scope
         scanf("%d",&n);
                     ^