N,H,W = map(int,input().split())
N4 = N//4
rm = N%4
ans = 4*N4**2
if rm == 0:
    pass
elif rm == 1:
    ans += 2*N4
elif rm == 2:
    ans += 2*N4+2*N4+1
elif rm == 3:
    ans += 2*N4+2*N4+1+2*N4+1
print(ans*((H-1)+(W-1)))