View Compilation Error

0_0_30189478_8364.cpp: In function 'int main()':
0_0_30189478_8364.cpp:10:8: error: 'cin' was not declared in this scope
  while(cin>>a>>b>>c){
        ^
0_0_30189478_8364.cpp:45:3: error: 'cout' was not declared in this scope
   cout<<(sum-2)<<endl; 
   ^
0_0_30189478_8364.cpp:45:18: error: 'endl' was not declared in this scope
   cout<<(sum-2)<<endl; 
                  ^