View Compilation Error

0_0_34398107_22883.cpp: In function 'void dfs(int)':
0_0_34398107_22883.cpp:26:5: error: 'dfn' was not declared in this scope
     dfn[u] = ++deep; id[deep] = u;
     ^
0_0_34398107_22883.cpp: In function 'int lca(int, int)':
0_0_34398107_22883.cpp:65:5: error: redefinition of 'int lca(int, int)'
 int lca(int u, int v) {
     ^
0_0_34398107_22883.cpp:36:5: note: 'int lca(int, int)' previously defined here
 int lca(int a, int b) {
     ^
0_0_34398107_22883.cpp:66:13: error: 'top' was not declared in this scope
     for ( ; top[u] != top[v]; u = fa[top[u]])
             ^
0_0_34398107_22883.cpp: In function 'void work()':
0_0_34398107_22883.cpp:82:56: error: 'dfn' was not declared in this scope
         for (ri i = 1; i <= A; ++i) read(a[i]), a[i] = dfn[a[i]];
                                                        ^
0_0_34398107_22883.cpp:84:56: error: 'dfn' was not declared in this scope
         for (ri i = 1; i <= B; ++i) read(b[i]), b[i] = dfn[b[i]];
                                                        ^