#include <bits/stdc++.h>
using namespace std;
struct Fast {
  Fast() {
    std::cin.tie(0);
    ios::sync_with_stdio(false);
  }
} fast;
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using pii = pair<int, int>;
using D = double;
using P = complex<D>;
using vs = vector<string>;
template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using minPQ = priority_queue<T, vector<T>, greater<T>>;
const int INF = 1001001001;
const ll LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7;
const D EPS = 1e-9;
const int dx[] = {0, 1, 0, -1, 1, -1, 1, -1},
          dy[] = {1, 0, -1, 0, 1, -1, -1, 1};
inline bool inside(int y, int x, int H, int W) {
  return y >= 0 && x >= 0 && y < H && x < W;
}
inline int in() {
  int x;
  cin >> x;
  return x;
}
inline ll IN() {
  ll x;
  cin >> x;
  return x;
}
inline vs split(const string& t, char c) {
  vs v;
  stringstream s(t);
  string b;
  while (getline(s, b, c)) v.emplace_back(b);
  return v;
}
template <typename T>
inline bool chmin(T& a, const T& b) {
  if (a > b) a = b;
  return a > b;
}
template <typename T>
inline bool chmax(T& a, const T& b) {
  if (a < b) a = b;
  return a < b;
}
template <typename T, typename S>
inline void print(const pair<T, S>& p) {
  cout << p.first << " " << p.second << endl;
}
template <typename T>
inline void print(const T& x) {
  cout << x << '\n';
}
template <typename T, typename S>
inline void print(const vector<pair<T, S>>& v) {
  for (auto&& p : v) print(p);
}
template <typename T>
inline void print(const vector<T>& v, string s = " ") {
  for (ll i = (0); i < (ll)(v.size()); ++i)
    cout << v[i] << (i != (ll)v.size() - 1 ? s : "\n");
}
template <typename T>
istream& operator>>(istream& is, vector<T>& vec) {
  for (T& x : vec) is >> x;
  return is;
}
template <typename T>
ostream& operator<<(ostream& os, vector<T>& vec) {
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i] << (i + 1 == vec.size() ? "" : " ");
  }
  return os;
}
signed main() {
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool flag = false;
  for (ll i = (0); i < (ll)(s.size()); ++i) {
    if (i == a)
      if (s[i] == '-')
        flag = true;
      else if (s[i] < '0' || s[i] > '9') {
        flag = false;
        break;
      } else
        flag = true;
  }
  flag ? print("Yes") : print("No");
  return 0;
}
