#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
const double eps = 1e-10;
const int MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll << 50;
template <typename T>
void printv(const vector<T>& s) {
  for (int i = 0; i < (int)(s.size()); ++i) {
    cout << s[i];
    if (i == (int)(s.size()) - 1)
      cout << endl;
    else
      cout << " ";
  }
}
int f(int a) { return (a * a + 4) / 8; }
ll memo[1000];
ll fib(ll n) {
  if (n == 0)
    return 2;
  else if (n == 1)
    return 1;
  else if (memo[n])
    return memo[n];
  else
    return memo[n] = fib(n - 1) + fib(n - 2);
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool ok = true;
  for (int i = 0; i < (int)(s.size()); ++i) {
    if (i == a + 1) {
      if (s[i] == '-') {
        ok = false;
        break;
      }
    } else {
      if ('0' <= s[i] && s[i] <= '9') {
        ok = false;
        break;
      }
    }
  }
  cout << (ok ? "Yes" : "No") << endl;
}
