foo.cc:3:7: error: expected nested-name-specifier before 'namespase'
 using namespase std;
       ^~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:7:2: error: 'cin' was not declared in this scope
  cin>>year>>month>>day;
  ^~~
foo.cc:7:2: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
foo.cc:8:5: error: 'mouth' was not declared in this scope
  if(mouth==1)
     ^~~~~
foo.cc:8:5: note: suggested alternative: 'month'
  if(mouth==1)
     ^~~~~
     month
foo.cc:58:41: error: expected primary-expression before '=' token
   if(year%400==0||(year%4==0&&year%100!==0))
                                         ^
foo.cc:60:13: warning: statement has no effect [-Wunused-value]
    days+days+1;
    ~~~~~~~~~^~
foo.cc:63:2: error: 'cout' was not declared in this scope
  cout<<days;
  ^~~~
foo.cc:63:2: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~

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