Problem:
Score : 200 points

Problem Statement

The postal code in Atcoder Kingdom is A+B+1 characters long, its (A+1)-th character is a hyphen -, and the other characters are digits from 0 through 9.

You are given a string S. Determine whether it follows the postal code format in Atcoder Kingdom.

Constraints

1≤A,B≤5

|S|=A+B+1

S consists of - and digits from 0 through 9.

Input

Input is given from Standard Input in the following format:

A B
S

Output

Print Yes if S follows the postal code format in AtCoder Kingdom; print No otherwise.

Sample Input 1

3 4
269-6650

Sample Output 1

Yes

The (A+1)-th character of S is -, and the other characters are digits from 0 through 9, so it follows the format.

Sample Input 2

1 1
---

Sample Output 2

No

S contains unnecessary -s other than the (A+1)-th character, so it does not follow the format.

Sample Input 3

1 2
7444

Sample Output 3

No

Solution in PyPy3 (2.4.0) (judge verdict: Accepted)

import sys
import math
from fractions import gcd
# import queue
# from collections import Counter
# from itertools import accumulate
# from functools import reduce

def lcm(a, b):
    return a * b // gcd(a, b)

def combination_count(n, r):
    return math.factorial(n) // (math.factorial(n - r) * math.factorial(r))

def permutations_count(n, r):
    return math.factorial(n) // math.factorial(n - r)

big_prime = 1000000007

"""
# 標準入力取得
## 文字列
 =  sys.stdin.readline().rstrip()
 =  list(sys.stdin.readline().rstrip())

## 数値
 =  int(sys.stdin.readline())
 =  map(int, sys.stdin.readline().split())
 =  list(map(int, sys.stdin.readline().split()))
 =  [list(map(int,list(sys.stdin.readline().split()))) for i in range(N)]
"""


A, B =  map(int, sys.stdin.readline().split())
S =  sys.stdin.readline().rstrip()

if S[A] != '-':
    print("No")
    exit()

X = map(int, S[:A:])
try:
    X = list(map(int, S[:A:]))
    Y = list(map(int, S[A + 1::]))
except:
    print("No")
    exit()

print("Yes")