/in/foo.c: In function 'main':
/in/foo.c:13:4: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   s=s*t/gcd(s,t);
   ~^~~~~~~~~~~~~
/in/foo.c: In function 'gcd':
/in/foo.c:30:10: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   return p;
          ^