local ffi = require 'ffi'
local C = ffi.C

ffi.cdef [[
void qsort(void *, size_t, size_t, int (*)(const void *, const void *));
]]

print((function (f, a, b)
	return f(a) == f(b) and "YES" or "NO"
end)(function (s)
	local t = ffi.new("char [?]", #s, s)
	C.qsort(t, #s, 1, ffi.cast("int (*)(const char *, const char *)", function (a,b) return a[0]-b[0] end))
	return ffi.string(t)
end, io.stdin:read("*l"), io.stdin:read("*l")))