/in/foo.cc: In function 'int main()':
/in/foo.cc:18:14: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return y?gcd(y,x%y):x;
           ~~~^~~~~~~
/in/foo.cc:20:5: note: 'y' was declared here
 int main()
     ^~~~
/in/foo.cc:57:9: warning: 'ans2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   printf("%lld/%lld\n",ans1/tmp,ans2/tmp);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:57:9: warning: 'ans1' may be used uninitialized in this function [-Wmaybe-uninitialized]