#include <bits/stdc++.h>
bool isNumber(char c) {
  if (c == '0') {
    return true;
  } else if (c == '1') {
    return true;
  } else if (c == '2') {
    return true;
  } else if (c == '3') {
    return true;
  } else if (c == '4') {
    return true;
  } else if (c == '5') {
    return true;
  } else if (c == '6') {
    return true;
  } else if (c == '7') {
    return true;
  } else if (c == '8') {
    return true;
  } else if (c == '9') {
    return true;
  } else {
    return false;
  }
}
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  int count = 0;
  if (S[A] == '-') {
    for (int i = 0; i < A; ++i) {
      if (isNumber(S[i])) {
        ++count;
      }
    }
    for (int i = A + 1; i < A + B + 1; ++i) {
      if (isNumber(S[i])) {
        ++count;
      }
    }
    count == A + B ? cout << "Yes" : cout << "No";
  } else {
    cout << "Yes" << endl;
  }
  return 0;
}
