C	B	A	Y
0	0	0	1
1	0	0	0
1	1	0	0
0	1	0	1
0	1	1	0
1	1	1	0
1	0	1	0
0	0	1	1

function: Y = (!C && !B && !A || !C && B && !A || !C && !B && A)