A,B=map(int,input().split())
S=str(input())
T=sorted(S[:])
p=0
if S[A]=="-":
  for i in range(1,len(S)):
    if 48<=ord(T[i])<=57:
      #print(ord(T[i]))
      p=1
    else:
      p=0
  #print(p)
  print("Yes" if p!=0 else "No")
else:
  print("No")