x1 = s1
x2 = s2
x3 = s3
x4 = s4
x5 = s5
x6 = s6
x7 = s7
x8 = s8
x9 = s9
x10 = s10
x11 = s11
x12 = s12
x13 = s13
x14 = s14
x15 = s15
x16 = s16
x17 = s17