# -*- coding: utf-8 -*-
import sys
import copy
import collections
from bisect import bisect_left
from bisect import bisect_right
	
def main():
	A, B = map(int, input().split(" "))
	S = input()
	tmp = S.split("-")
	
	if tmp[0].isdecimal() == False or tmp[1].isdecimal() == False:
		print("No")
		sys.exit()
	
	if len(tmp[0]) == A and len(tmp[1]) == B:
		print("Yes")
	else:
		print("No")
	
	
if __name__ == "__main__":
	main()
