------
## 最终结论
```python
def probability_nth_person_gets_seat(n):
    if n == 1:
        return 1.0
    else:
        return 0.5

# Example usage
n = int(input("Enter the number of passengers (n): "))
print(f"The probability that the n-th person can get his own seat is: {probability_nth_person_gets_seat(n):.5f}")
```