给定一个正整数 $n$。
你需要求出 $n \bmod 1, n \bmod 2, \dots, n \bmod (n - 1)$ 中不同整数的个数。
输入格式
输入的第一行包含一个整数 $n$ ($2 \le n \le 10^9$)。
输出格式
输出一个整数：$n \bmod 1, n \bmod 2, \dots, n \bmod (n - 1)$ 中不同整数的个数。
样例
样例输入 1
2
样例输出 1
1
样例输入 2
3
样例输出 2
2
QOJ.ac
QOJ
Time Limit: 2 s
Memory Limit: 256 MB
Total points: 100
Difficulty:
[show]
Hackable ✓
#4249. 模运算魔法
Statistics
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This problem is prepared by
300iq .
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