#include <bits/stdc++.h>
using namespace std;
bool IsValidAddress(int A, int B, const string &S) {
  int n = S.length();
  if (n != A + B + 1) {
    return false;
  }
  for (int i = 0; i < n; i++) {
    if (i == A) {
      if (S[i] != '-') {
        return false;
      }
    } else {
      if (S[i] < '0' || '9' < S[i]) {
        return false;
      }
    }
  }
  return true;
}
int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  if (IsValidAddress(A, B, S)) {
    printf("Yes\n");
  } else {
    printf("No\n");
  }
  return 0;
}
