#include <iostream>
#include <string>
#include <algorithm>
#include <math.h>
#include <map>
#include <set>
using namespace std;
typedef long long ll;
#define rep(i,s,n)for(ll i = s;i<n;i++)
#define repe(i,s,n)for(ll i = s;i<=n;i++)

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

	if (s[A] == '-') {
		rep(i, 0, A) {
			if (s[i] >= '0' && s[i] <= '9') {
			}
			else {
				cout << "No" << endl;
				return 0;
			}
		}
		repe(i, A + 1, A + B + 1) {
			if (s[i] >= '0' && s[i] <= '9') {
			}
			else {
				cout << "No" << endl;
				return 0;
			}
		}
	}
	else {
		cout << "No" << endl;
		return 0;
	}

	cout << "Yes" << endl;

	return 0;
}