/in/foo.c: In function 'main':
/in/foo.c:5:4: warning: statement with no effect [-Wunused-value]
  k1<k2;
  ~~^~~
/in/foo.c:5:4: warning: 'k1' is used uninitialized in this function [-Wuninitialized]
  k1<k2;
  ~~^~~
/in/foo.c:5:4: warning: 'k2' is used uninitialized in this function [-Wuninitialized]