def f(s,a,b,c) return s[a]+s[b]+s[c] end a=gets.chomp n=gets.to_i s=[] if n%2==0 then s<0 && (n-1)%2==0 then s<1 && (n-2)%2==0 then s<2 && (n-3)%2==0 then s<