#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  int ans = 0;
  string s;
  cin >> a >> b;
  getchar();
  cin >> s;
  int i, j;
  for (i = 0; i < a; i++) {
    if (s[i] >= '9' || s[i] <= '0') break;
  }
  if (i == a - 1) ans++;
  if (s[a] == '-') ans++;
  for (j = a + 1; j < a + b + 1; j++) {
    if (s[i] >= '9' || s[i] <= '0') break;
  }
  if (j == b) ans++;
  if (ans == 3)
    puts("Yes");
  else
    puts("No");
  return 0;
}
