#include <bits/stdc++.h>
using namespace std;
template <typename T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <typename T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <class T>
void chmax(T& a, T b) {
  if (a > b) a = b;
}
template <class T>
void chmin(T& a, T b) {
  if (a < b) b = a;
}
int main() {
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool flag = true;
  if (s.size() == a + b + 1 && s[a] == '-') {
    for (int i = 0; i < a; i++) {
      if (0 <= s[i] - '0' && s[i] - '0' <= 9) continue;
      flag = false;
    }
    for (int i = a + 1; i < a + b + 1; i++) {
      if (0 <= s[i] - '0' && s[i] - '0' <= 9) continue;
    }
  } else {
    flag = false;
  }
  if (flag)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
