print((function (fh)
	local h,n,r={},0,0
	for _=1,tonumber(fh:read("*l")) do
		local k=#fh:read("*l") h[k]=h[k]~=nil and h[k]+1 or 0
	end
	for k,v in pairs(h) do if v==n and k>r or v>n then r,n=k,v end end
	return r-2
end)(io.stdin))