#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T& val) {
  std::fill((T*)array, (T*)(array + N), val);
}
struct Edge {
  int from, to, weight;
  bool operator<(const Edge& obj) const { return weight < obj.weight; }
  bool operator>(const Edge& obj) const { return weight > obj.weight; }
};
struct UnionFind {
  vector<int> data;
  UnionFind(int size) : data(size, -1) {}
  bool unionSet(int x, int y) {
    x = root(x);
    y = root(y);
    if (x != y) {
      if (data[y] < data[x]) swap(x, y);
      data[x] += data[y];
      data[y] = x;
    }
    return x != y;
  }
  bool findSet(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  bool isroot(int x) { return data[x] < 0; }
  int size(int x) { return -data[root(x)]; }
};
int main() {
  int a, b;
  cin >> a >> b;
  string s;
  bool ok = true;
  for (int i = (0); (a) > i; i++) {
    if (s[i] == '-') ok = false;
  }
  if (s[a] != '-') ok = false;
  for (int i = (a + 1); (b + a + 1) > i; i++) {
    if (s[i] == '-') ok = false;
  }
  cout << (ok ? "Yes" : "No") << endl;
  return 0;
}
