Which of the following base 2 sums is the largest?

W) \(1+1111\) [one plus one one one one one]

X) \(100+1001\) [one zero zero plus one zero zero one]

Y) \(110+1000\) [one one zero plus one zero zero zero]

Z) \(111+111\) [one one one plus one one one]
W) \(1+1111\)