/in/foo.cc:2:7: error: expected nested-name-specifier before 'manespace'
 using manespace std;
       ^~~~~~~~~
/in/foo.cc:3:24: error: two or more data types in declaration of 'gcd'
 int int gcd(int m,int n)
                        ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:11:2: error: 'cin' was not declared in this scope
  cin>>m>>n;
  ^~~
/in/foo.cc:11:2: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
/in/foo.cc:12:2: error: 'cout' was not declared in this scope
  cout<<"gcd="<<gcd(m,n)<<rndl;
  ^~~~
/in/foo.cc:12:2: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~
/in/foo.cc:12:23: error: 'gcd' was not declared in this scope
  cout<<"gcd="<<gcd(m,n)<<rndl;
                       ^
/in/foo.cc:12:26: error: 'rndl' was not declared in this scope
  cout<<"gcd="<<gcd(m,n)<<rndl;
                          ^~~~