View Compilation Error

0_0_38405123_26403.cpp: In function 'int main()':
0_0_38405123_26403.cpp:3:2: error: 'string' was not declared in this scope
  string str;
  ^
0_0_38405123_26403.cpp:4:16: error: 'cin' was not declared in this scope
  while(getline(cin,str))
                ^
0_0_38405123_26403.cpp:4:20: error: 'str' was not declared in this scope
  while(getline(cin,str))
                    ^
0_0_38405123_26403.cpp:4:23: error: 'getline' was not declared in this scope
  while(getline(cin,str))
                       ^
0_0_38405123_26403.cpp:22:3: error: 'cout' was not declared in this scope
   cout<<ct<<endl;
   ^
0_0_38405123_26403.cpp:22:13: error: 'endl' was not declared in this scope
   cout<<ct<<endl;
             ^