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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

//大文字->小文字 tolower(),逆はtoupper()
//int a = stoi(c); 文字列をintへ
//途中の出力をそのまま残さない
//数値計算 個数以外はdouble
//map<キー,値> p は辞書。p[キー] = 値
//map 全探索
//auto begin = p.begin(), end = p.end();
//for (auto it = begin; it != end; i++) {}
//mapのキー：it->first mapのバリュー：it->second
//絶対値 abs()
//入力は空白で切れる
//大文字判定 isupper(文字) 小文字判定 islower(文字)
//do{}while(next_permutation(ALL(配列)))
#include <bits/stdc++.h>
#define rep(i,N) for(int i = 0; i < N;i++)
#define ALL(a) (a).begin(),(a).end()
#define ll long long int
using namespace std;

// K進数でのNの桁数
ll dig(ll N,ll K) {
	ll dig = 0;
	while (N) {
		dig++;
		N /= K;
	}
	return dig;
}
// x,yの最大公約数
ll gcd(ll x, ll y) {
	ll r;
	while (x%y) {
		r = x % y;
		x = y;
		y = r;
	}
	return y;
}

int main() {
	int A, B; cin >> A >> B;
	string S; cin >> S;

	if (S[A] != '-') {
		cout << "No" << endl; return 0;
	}
	if (S.length() != A + B + 1) {
		cout << "No" << endl; return 0;
	}
	for (int i = 0; i < S.length(); i++) {
		if (i != A && S[i] == '-') {
				cout << "No" << endl;
				return 0;
		}
	}

	cout << "Yes" << endl;
}