######## LIST PRACTICE ####### First index of element

 Problem Statement

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Take an array with n elements with possibly duplicate elements as the input. The task is to find the index of the first occurrences of the element x in the array and, if it is not present, return -1.

Input Format:

The first line contains an integer N representing the size of the array.

The next line contains N space-separated integers representing the elements of the array.

The last line contains an integer 'x' whose index has to be found.

Output Format:

The only line of the output prints the Index or -1.
Constraints:
1 <= N <= 10^3
1 <= arr[i] <= 10^9
1 <= x < N
Sample Input 1 :
8
7 5 2 11 2 43 1 1
2
Sample Output 1 :
2
Explanation Of Sample Input 1:
2 is present twice in the input array and the first time it appears is at index 2.
Sample Input 2 :
8
7 5 2 11 2 43 1 1
10
Sample Output 2 :
-1
Explanation Of Sample Input 2:
10 is not present in the array so the output is -1.





n = int(input())   
lst=(input().split())
x=input()

try:
    print( lst.index(x) )
except ValueError :
    print(-1)

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