View Compilation Error

0_0_33729662_11489.cpp: In function 'void dfs(int, int)':
0_0_33729662_11489.cpp:28:3: error: 'ans' was not declared in this scope
   ans = (ans + 1ll * dp[v][0] * (num_one - dp[v][1]) % mod*it.second) % mod;
   ^
0_0_33729662_11489.cpp:28:34: error: 'num_one' was not declared in this scope
   ans = (ans + 1ll * dp[v][0] * (num_one - dp[v][1]) % mod*it.second) % mod;
                                  ^
0_0_33729662_11489.cpp:29:34: error: 'num_zero' was not declared in this scope
   ans = (ans + 1ll * dp[v][1] * (num_zero - dp[v][0]) % mod*it.second) % mod;
                                  ^