View Compilation Error

0_0_30333405_25429.cpp: In function 'void Dfs(int, int)':
0_0_30333405_25429.cpp:24:9: error: 'v' was not declared in this scope
     for(v:vc[u]){
         ^
0_0_30333405_25429.cpp:30:5: error: expected primary-expression before 'for'
     for(auto v:vc[u]){
     ^
0_0_30333405_25429.cpp:30:5: error: expected ')' before 'for'