View Compilation Error

0_0_16699781_2979.cpp:14:1: error: '_int64' does not name a type
 _int64 ans ; 
 ^
0_0_16699781_2979.cpp: In function 'void dfs(int, int)':
0_0_16699781_2979.cpp:46:3: error: 'ans' was not declared in this scope
   ans = (ans + sum[x]) % Z;  
   ^
0_0_16699781_2979.cpp: In function 'int main()':
0_0_16699781_2979.cpp:63:5: error: 'ans' was not declared in this scope
     ans = 0 ; 
     ^