letters$ = "BO,XK,DQ,CP,NA,GT,RE,TG,QD,FS,JW,HU,VI,AN,OB,ER,FS,LY,PC,ZM"

sub canMake(letters$, word$)
	local i, j, p, n, pairs$(1)
	
	n = token(letters$, pairs$(), ",")
	word$ = upper$(word$)
	
	for i = 1 to len(word$)
		for j = 1 to n
			p = instr(pairs$(j), mid$(word$, i, 1))
			if p then
				pairs$(j) = ""
				break
			end if
		next j
		if not p return false
	next i
	return true
end sub

print "a = ", canMake(letters$, "a")	// 1 = true
print "bark = ", canMake(letters$, "Bark")	// 1
print "book = ", canMake(letters$, "BooK")	// 0 = false
print "treat = ", canMake(letters$, "TREAt")	// 1
print "common = ", canMake(letters$, "common")	// 0
print "squad = ", canMake(letters$, "squad")	// 1
print "confuse = ", canMake(letters$, "confuse")	// 1