#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  int l = a + b + 1;
  for (int i = (0); i < (l); ++i) {
    char c = s[i];
    if (i == a) {
      if (c == '-') continue;
    } else {
      if ('0' <= c and c <= '9') continue;
    }
    printf("No");
    return 1;
  }
  printf("Yes");
  return 0;
}
