function caesar(s, k) {
	u = ascii(s)
	i = selectindex(u:>=65 :& u:<=90)
	if (length(i)>0) u[i] = mod(u[i]:+(k-65), 26):+65
	i = selectindex(u:>=97 :& u:<=122)
	if (length(i)>0) u[i] = mod(u[i]:+(k-97), 26):+97
	return(char(u))
}

caesar("layout", 20)
  fusion