A, B = [int(ab) for ab in input().split()]
S = input()
N = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
for i in range(A+B):
  if i == A and S[i] == "-":
    continue
  elif i != A and S[i] in N:
    continue
  else:
    print("No")
else:
  print("Yes")