Attendance Check

A teacher leads a spring outing. There are \(N\) students in the class, each with a unique identification number from \(0\) to \(N-1\). At the gathering point, every student who has arrived reports his own ID. Note that some students may report their ID multiple times. Your task is to help the teacher determine which students did not arrive.

inputFormat

The input consists of two lines. The first line contains a single integer \(N\) representing the total number of students. The second line contains space-separated integers denoting the IDs reported by the students. It is guaranteed that each present student reports his ID at least once, although some IDs might appear more than once.

outputFormat

Print the IDs of the students who did not arrive, in increasing order and separated by a single space. If all students have arrived, output nothing.

sample

5
0 1 2 3 4