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 Python (3.4.3) (judge verdict: Wrong Answer)

a = list(map(int,input().split()))
S = input()
result = "No"
flag = True
if S.count("-"):
    b = list(S.split("-"))
    a.sort()
    b.sort()
elif S.count("-") == 1 and (S.find("-") == 0 or S.find("-") == len(S)-1):
    if sum(a) == len(S)+1:
        result = "Yes"
        flag = False
else:
    flag = False

if not flag == False:
    if a[0] == len(b[0]) and a[1] == len(b[1]):
        result = "Yes"

print(result)