View Compilation Error

0_0_38572824_15279.cpp: In function 'int main()':
0_0_38572824_15279.cpp:7:5: error: 'cin' was not declared in this scope
     cin>>t;
     ^~~
0_0_38572824_15279.cpp:7:5: note: suggested alternative: 'main'
     cin>>t;
     ^~~
     main
0_0_38572824_15279.cpp:7:10: error: 't' was not declared in this scope
     cin>>t;
          ^
0_0_38572824_15279.cpp:25:9: error: 'cout' was not declared in this scope
         cout<<ans<<endl;
         ^~~~
0_0_38572824_15279.cpp:25:20: error: 'endl' was not declared in this scope
         cout<<ans<<endl;
                    ^~~~
0_0_38572824_15279.cpp:25:20: note: suggested alternative: 'enum'
         cout<<ans<<endl;
                    ^~~~
                    enum