x5, x4, x3, x2, x1, s, 
s-x1*(1+x2+x3+x4+x5)
s-x2*(1+x1+x3+x4+x5)
s-x3*(1+x1+x2+x4+x5)
s-x4*(1+x1+x2+x3+x5)
s-x5*(1+x1+x2+x3+x4)
