View Compilation Error

0_0_19181333_4172.cpp: In function 'int main()':
0_0_19181333_4172.cpp:6:2: error: 'cin' was not declared in this scope
  cin>>N;
  ^
0_0_19181333_4172.cpp:12:3: error: 'cout' was not declared in this scope
   cout<<"Scenario #"<<i<<':'<<endl;
   ^
0_0_19181333_4172.cpp:12:31: error: 'endl' was not declared in this scope
   cout<<"Scenario #"<<i<<':'<<endl;
                               ^
0_0_19181333_4172.cpp:16:22: error: incomplete type 'std::ios {aka std::basic_ios<char>}' used in nested name specifier
    cout<<setiosflags(ios::fixed)<<setprecision(2)<<a*b+0.41<<endl;
                      ^