A9523. Forgotten Episode
编程题
普及/提高-
知识点
题目描述
Polycarpus adores TV series. Right now he is ready to finish watching a season of a popular sitcom "Graph Theory". In total, the season has $n$ episodes, numbered with integers from $1$ to $n$ .
Polycarpus watches episodes not one by one but in a random order. He has already watched all the episodes except for one. Which episode has Polycaprus forgotten to watch?
Polycarpus watches episodes not one by one but in a random order. He has already watched all the episodes except for one. Which episode has Polycaprus forgotten to watch?
输入格式
The first line of the input contains integer $n$ $(2<=n<=100000)$ — the number of episodes in a season. Assume that the episodes are numbered by integers from $1$ to $n$ .
The second line contains $n-1$ integer $a_{1},a_{2},...,a_{n}$ $(1<=a_{i}<=n)$ — the numbers of episodes that Polycarpus has watched. All values of $a_{i}$ are distinct.
The second line contains $n-1$ integer $a_{1},a_{2},...,a_{n}$ $(1<=a_{i}<=n)$ — the numbers of episodes that Polycarpus has watched. All values of $a_{i}$ are distinct.
输出格式
Print the number of the episode that Polycarpus hasn't watched.
输入输出样例
输入 #1
10 3 8 10 1 7 9 6 5 2
输出 #1
4