/in/foo.cc: In function 'int main()':
/in/foo.cc:182:24: error: 'str3' was not declared in this scope
          div(str1,str2,str3,str4);
                        ^~~~
/in/foo.cc:182:29: error: 'str4' was not declared in this scope
          div(str1,str2,str3,str4);
                             ^~~~