#include <bits/stdc++.h>
using namespace std;
static const int MAX = 50;
static const long long INFTYL = 9223372036854775807;
static const int INFTY = 2147483647;
long long mod = 1000000007;
int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  bool valid = false;
  if (S[A] != '-' || S.size() != A + B + 1) {
    valid = false;
  } else {
    for (long long i = 0; i < (long long)A + B + 1; i++) {
      if (i != A) {
        int t = S[i] - '0';
        if (t >= 0 && t <= 9) {
          valid = true;
        }
      }
    }
  }
  string ans;
  if (valid) {
    ans = "Yes";
  } else {
    ans = "No";
  }
  cout << ans << endl;
  return 0;
}
