#include <bits/stdc++.h>
using namespace std;
int main() {
  int find = 0, a, b;
  string str;
  scanf("%d %d", &a, &b);
  cin >> str;
  if (str[a] == '-') {
    for (int i = a + 1; i <= a + b; i++) {
      if (str[i] >= '0' && str[i] <= '9')
        ;
      else {
        find = 1;
        break;
      }
    }
    if (find == 1)
      printf("No\n");
    else
      printf("Yes\n");
  } else
    printf("No\n");
}
