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)

/*  ***  In The Name of God ... ***  */ 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

#define int long long
#define all(v) v.begin() , v.end()
#define pb push_back
#define endl '\n' 
template<typename T> inline bool smin(T &a, const T &b){ return b < a ? a = b,1:0;}
template<typename T> inline bool smax(T &a, const T &b){ return a < b ? a = b,1:0;}

int a , b ;
string s ; 

int32_t main()
{
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> a >> b >> s ;
	for ( int i = 0 ; i < a + b + 1 ; ++ i ) {
		if ( i == a )
			if ( s [ i ] != '-' )
				return cout << "No\n" , 0 ;
		if ( i != a )
			if ( ! ( s [ i ] >= '0' && s [ i ] <= '9' )  )
			     return cout << "No\n" , 0 ; 
	}
	cout << "Yes\n" ; 
}