#include <iostream>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <vector>
using namespace std;

int main(void) {

	int A, B;
	string S;
	cin >> A >> B >> S;

	if (S.size() <= A)
	{
		cout << "No" << endl;
		return 0;
	}

	if (S.substr(A, 1) != "-")
	{
		cout << "No" << endl;
		return 0;
	}

	string front = S.substr(0, A);
	if (all_of(front.cbegin(), front.cend(), isdigit) == false)
	{
		cout << "No" << endl;
		return 0;
	}

	string rear = S.substr(A + 1);
	if (all_of(rear.cbegin(), rear.cend(), isdigit) == false)
	{
		cout << "No" << endl;
		return 0;
	}

    cout << "Yes" << endl;
	return 0;
}