View Compilation Error

0_0_19240266_2519.cpp:1:1: error: 'string' does not name a type
 string s;
 ^
0_0_19240266_2519.cpp:2:5: error: 'cin' does not name a type
     cin>>T;
     ^
0_0_19240266_2519.cpp:3:5: error: expected unqualified-id before 'while'
     while(T--)
     ^