hello.cpp:4:3: error: ‘cout’ was not declared in this scope

I am a beginner in C++ and trying to execute the following code.

    #include<iostream>
    int main()
    {
      cout<<"hellow world";
      return 0;
    }

In this code I am getting the following errors

    hello.cpp: In function ‘int main()’:
    hello.cpp:4:3: error: ‘cout’ was not declared in this scope
    cout<<"hellow world";
    ^
    hello.cpp:4:3: note: suggested alternative:
    In file included from hello.cpp:1:0:
    /usr/include/c++/5/iostream:61:18: note:   ‘std::cout’
    extern ostream cout;  /// Linked to standard output

Please help to fix the code...