a,b=map(int,input().split())
s=str(input())
e=[0,1,2,3,4,5,6,7,8,9]
for i in range(len(s)):
  if a=i:
    if s[i]!='-':
      print("No")
      exit()
  else:
    if s[i] not in e:
      print("No")
      exit()

print("Yes")