Problems
Lost card
Lost card
For the board game the deck of cards is used with numbers from $1$ to $n$ (positive integer $n$ does not exceed $10^6$). One card is lost. Find it.
\InputFile
The first number is $n$. Then goes $n - 1$ numbers of left cards.
\OutputFile
Print the number of lost card.
Input example #1
5 1 2 3 4
Output example #1
5
Input example #2
4 3 2 4
Output example #2
1