func main()
	var s: []char :: cui@input()
	var t: []char :: cui@input()
	if(^t = 1)
		for i(0, ^s - 1)
			if(s[i] = t[0])
				do cui@print("-1\n")
				ret
			end if
		end for
		do cui@print("0\n")
		ret
	end if
	var tpos: int :: 0
	var ans: int :: 0
	for i(0, ^s - 1)
		if(s[i] = t[tpos])
			do tpos :+ 1
			if(tpos = ^t)
				do ans :+ 1
				do tpos :: 0
				if(s[i] = t[0])
					do tpos :+ 1
				end if
			end if
		else
			do i :- tpos
			do tpos :: 0
		end if
	end for
	do cui@print("\{ans}\n")
end func