test_case = gets.chomp.to_i
flag = Array.new
test_case.times{flag << true}
test_case.times do
	gets.chomp.split.each_with_index{|val, i| flag[i] = false unless val == "nyanpass" || val == "-"}
end
puts flag.count(true) == 1 ? flag.index(true) + 1 : -1