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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define ri register
#define int long long
#define E (n+1)
using namespace std; const int N=200010;
inline int read()
{
    int s=0, w=1; ri char ch=getchar();
    while(ch<'0'||ch>'9') { if(ch=='-') w=-1; ch=getchar(); }
    while(ch>='0'&&ch<='9') s=(s<<3)+(s<<1)+(ch^48), ch=getchar();
    return s*w;
}
signed main()
{
    int a,b; string s;
    cin>>a>>b>>s;
    int n=s.length();
    int flg=0, pp=1;
    for(ri int i=0;i<n;i++)
    {
        if(i==a&&s[i]=='-') { flg=1; continue; }
        if(i!=a&&s[i]>='0'&&s[i]<='9'&&pp) pp=1;
        else if(i!=a) pp=0;
    }
    if(pp&&flg) puts("Yes");
    else puts("No");
    return 0;
}