func main()
	var n: int :: cui@inputInt()
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	for i(1, n)
		var p: int :: cui@inputInt()
		if(p % 2 = 1)
			do a :- 1
		end if
		if(p > 1)
			do b :- 1
		end if
		
		if(a < 0 | b < 0)
			do cui@print("\{i}\n")
			ret
		end if
	end for
	
	do cui@print("-1\n")
end func