View Compilation Error

0_0_36286406_29996.cpp:13:1: error: 'unordered_map' does not name a type
 unordered_map<LL,LL>mp;
 ^
0_0_36286406_29996.cpp: In function 'void init(long long int, long long int)':
0_0_36286406_29996.cpp:26:2: error: 'mp' was not declared in this scope
  mp.clear();
  ^
0_0_36286406_29996.cpp: In function 'long long int solve(long long int)':
0_0_36286406_29996.cpp:41:6: error: 'mp' was not declared in this scope
   if(mp[res])
      ^
0_0_36286406_29996.cpp: In function 'int main()':
0_0_36286406_29996.cpp:51:3: error: 'mp' was not declared in this scope
   mp.clear();
   ^