#include <bits/stdc++.h>
using namespace std;
const int INF(1 << 30);
const long long LLINF(1LL << 55LL);
const int pi = 3.1415926536;
const int MOD = 1000000007;
const int MAX = 510000;
void Main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  int cnt = 0;
  for (long long i = (0); i < (a + b + 1); ++i) {
    if (cnt == 2) {
      break;
    }
    if (s[i] == '-') {
      cnt++;
    }
  }
  if (cnt == 1) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
int main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  Main();
}
