#include <bits/stdc++.h>
int main() {
  int a, b, valid;
  scanf("%d %d", &a, &b);
  char str[a + b + 1];
  scanf("%s", str);
  for (int i = 0; i < a + b; i++) {
    if ((30 <= str[i] && str[i] <= 39) || (str[a] == '-')) {
      valid = 1;
    } else {
      valid = 0;
      break;
    }
  }
  if (valid == 1) {
    printf("Yes\n");
  } else {
    printf("No\n");
  }
  return 0;
}
