#include <bits/stdc++.h>
using namespace std;
const int dirx[] = {-2, -1, 1, 2, 1, -1};
const int diry[] = {0, 1, 1, 0, -1, -1};
inline void debugMode() {}
int n, a[100100], b;
string s;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> b;
  cin >> s;
  if (s[n + 1] == '-') {
    for (int i = 0; i < s.size(); i++) {
      if (i == n + 1) continue;
      if (!isdigit(s[i])) return cout << "No", 0;
    }
  } else
    return cout << "No", 0;
  cout << "Yes";
  return 0;
}
