View Compilation Error

0_0_16652882_3914.cpp:13:12: error: expected unqualified-id before '=' token
 long long  =1e9+7;
            ^
0_0_16652882_3914.cpp: In function 'void dfs1(int)':
0_0_16652882_3914.cpp:36:11: error: 'mod' was not declared in this scope
    dp[u]%=mod;
           ^
0_0_16652882_3914.cpp: In function 'void dfs2(int)':
0_0_16652882_3914.cpp:42:34: error: 'mod' was not declared in this scope
   long long x=quick_plus(dp[u]+1,mod-2,mod);
                                  ^
0_0_16652882_3914.cpp: In function 'int main()':
0_0_16652882_3914.cpp:81:9: error: 'mod' was not declared in this scope
    ans%=mod;
         ^
0_0_16652882_3914.cpp:83:25: error: 'mod' was not declared in this scope
   printf("%I64d\n",(ans+mod)%mod);
                         ^