d1, d2 = map(float, input().split())
p=d1*d2/2
print("Pole rombu, ktorego przekatne sa rowne", d1, "i", d2, "wynosi", p)
ZDEsIGQyID0gbWFwKGZsb2F0LCBpbnB1dCgpLnNwbGl0KCkpCnA9ZDEqZDIvMgpwcmludCgiUG9sZSByb21idSwga3RvcmVnbyBwcnpla2F0bmUgc2Egcm93bmUiLCBkMSwgImkiLCBkMiwgInd5bm9zaSIsIHAp