/in/foo.cc: In function 'void Work1()':
/in/foo.cc:17:6: warning: unused variable 'sup' [-Wunused-variable]
  int sup, a, b, pos = 0, t = 1;
      ^
/in/foo.cc: In function 'void Work2()':
/in/foo.cc:50:37: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
  GCD = gcd(a, b), a /= GCD, b /= GCD;
                                     ^