#include <bits/stdc++.h>
int main() {
  int i, a, b, flag;
  while (scanf("%d %d", &a, &b) != EOF) {
    char str[a + b + 1], c;
    flag = 1;
    c = getchar();
    scanf("%[0-9-]s", str);
    for (i = 0; str[i] != '\0'; i++) {
      if (i == a) continue;
      if (str[a] == '-' && str[i] != '-') flag = 0;
    }
    if (flag == 0)
      printf("Yes\n");
    else
      printf("No\n");
  }
  return 0;
}
