# -*- coding: utf-8 -*-

import sys

a, b = [int(e) for e in raw_input().split()]
s = raw_input().split()[0]

sa = s[:a]
sh = s[a:a+1]
sb = s[a+1:]

if len(sa) == a:
    if  sa.isdigit():
        if sh == '-':
            if len(sb) == b:
                if sb.isdigit():
                    sys.stdout.write('Yes\n')
                    sys.stdout.flush()
                    sys.exit(0)

sys.stdout.write('No\n')
sys.stdout.flush()
