a,b = map(int,input())
n = input()
co = 0
if len(n) == a+b+1:
  for i in range(a+b+1):
    if n[i] == "-":
      if i != a:
        print("No")
        exit()
      else:
        co = 1
  if co == 1:
    print("Yes")
  else:
    print("No")
    
else:
  print("No")
  exit()