A,B=map(int,input().split())
S=str(input())
T=sorted(S[:])
p=0
if (A+B+1)!=len(S):
  print("No")
else:
  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")