"""
author : halo2halo
date : 24, Jan, 2020
"""

import sys

# import itertools
# import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

A, B = map(int, readline().split())
S = readline().decode('utf8').rstrip()
T=S[:A]+S[A+1:]
bl = S[A] == '-' and '-' in T

print('Yes' if bl else 'No')
