#include <bits/stdc++.h>
using namespace std;

int A, B;
string S;
bool ans = true;

void solve() {
  for (int i = 0; i < A; ++i) {
    if (i == A + 1){
      if (S[i] != '-'){
        ans = false;
      }
    }else{
      for (int j = 0; j < 10; ++j){
        if (S[i] != j){
          ans = false;
        }
      }
    }
  }
  if (ans){
    cout << Yes << endl;
  }else{
    cout << No << endl;
  }
}

int main() {
  cin >> A >> B;
  cin >> S;
  solve();
  return 0;
}