#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  char ch[15];
  scanf("%d %d", &a, &b);
  scanf("%s", ch);
  if (ch[a] != '-')
    printf("Yes\n");
  else {
    bool f = 1;
    for (int i = 0; i < (a + b + 1);) {
      if (i == a) {
        i++;
      } else if (ch[i] >= '0' && ch[i] <= '9') {
        i++;
      } else {
        f = 0;
        break;
      }
    }
    printf("%s\n", f ? "Yes" : "No");
  }
  return 0;
}
