def issigit(s):
  return all(c in '0123456789' for c in s)

def check(s, a, b):
  if len(s) != a + b + 1:
    return False
  
  if not isdigit(s[:a]):
    return False
  
  if s[a] != '-':
    return False
  
  if not isdigit(s[-b:]):
    return False
  
  return True
  
a, b = map(int, input().split())
s = input()
if check(s, a, b):
  print('Yes')
else:
  print('No')
