#include <bits/stdc++.h>
using namespace std;
int isFlag(string S, int N, int start) {
  for (int i = 0; i < N; i++) {
    switch (S[i + start]) {
      case '1':
        return 0;
      case '2':
        return 0;
      case '3':
        return 0;
      case '4':
        return 0;
      case '5':
        return 0;
      case '6':
        return 0;
      case '7':
        return 0;
      case '8':
        return 0;
      case '9':
        return 0;
    }
  }
  return 1;
}
int main() {
  int A, B;
  string S;
  int flag = 0;
  cin >> A >> B >> S;
  if (S.size() != A + B + 1)
    flag += 1;
  else {
    flag += isFlag(S, A, 0);
    if (S[A] != '-') flag += 1;
    flag += isFlag(S, B, A + 2);
  }
  if (flag == 0)
    cout << "Yes\n";
  else
    cout << "No\n";
  return 0;
}
