View Compilation Error

0_0_38799631_3167.cpp:9:1: error: 'unordered_map' does not name a type
    9 | unordered_map<int, int> s;
      | ^~~~~~~~~~~~~
0_0_38799631_3167.cpp: In function 'long long int dfs(long long int)':
0_0_38799631_3167.cpp:28:12: error: 's' was not declared in this scope
   28 |         if(s[x]) return s[x];
      |            ^
0_0_38799631_3167.cpp:29:9: error: 's' was not declared in this scope
   29 |         s[x] = min(dfs(x / 2) + 1 + x % 2, dfs(x / 3) + 1 + x % 3);
      |         ^