View Compilation Error

0_0_38844230_21191.cpp:1:1: error: 'unordered_map' does not name a type
    1 | unordered_map<int,int> mp;
      | ^~~~~~~~~~~~~
0_0_38844230_21191.cpp:3:1: error: 'll' does not name a type
    3 | ll dfs(int x){
      | ^~
0_0_38844230_21191.cpp: In function 'void solve()':
0_0_38844230_21191.cpp:23:9: error: 'll' was not declared in this scope
   23 |         ll n;cin>>n;
      |         ^~
0_0_38844230_21191.cpp:23:14: error: 'cin' was not declared in this scope
   23 |         ll n;cin>>n;
      |              ^~~
0_0_38844230_21191.cpp:23:19: error: 'n' was not declared in this scope
   23 |         ll n;cin>>n;
      |                   ^
0_0_38844230_21191.cpp:24:5: error: 'ans' was not declared in this scope
   24 |     ans=2e9;
      |     ^~~
0_0_38844230_21191.cpp:25:9: error: 'dfs' was not declared in this scope
   25 |     ans=dfs(n);
      |         ^~~
0_0_38844230_21191.cpp:26:5: error: 'cout' was not declared in this scope
   26 |     cout<<ans<<'\n';
      |     ^~~~