/in/foo.cc: In function 'int main(int, const char**)':
/in/foo.cc:14:31: error: 'strlen' was not declared in this scope
         for(int i=0;i<strlen(a);i++)
                               ^
/in/foo.cc:16:31: error: 'strlen' was not declared in this scope
         for(int i=0;i<strlen(b);i++)
                               ^