C :

#include<stdio.h>
int main(){
	int m,n,i;
	scanf("%d",&m);
	int a[m];
	for(i=0;i<m;i++){
		scanf("%d",&a[i]);
	} 
	scanf("%d",&n);
	int f=0;
	for(i=0;i<m;i++){
		if(a[i]==n){
			f=1;
			break;
		}
	}
	if(f==0){
		printf("%d",-1);
	}else{
	    printf("%d",i+1);	
	}

	return 0;
	
}

C++ :

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main(){
	int a[100],n,s;
	bool f=false;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
	}
	cin>>s;
	for(int i=0;i<n;i++){
		if(a[i]==s){
			cout<<i+1<<endl;
			f=true;
			break;
		}
	}
	
	if(f==false){
		cout<<"-1"<<endl;
	}
}

Pascal :

var
i,n,m:longint;
a:array[1..100] of longint;
begin
readln(n);
for i:=1 to n do read(a[i]);
readln(m);
for i:=1 to n do if a[i]=m then begin write(i);exit;end;
end.

Java :

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int x = in.nextInt();
		int[] a = new int[x];
		int b=-1;
		for(int i=0;i<a.length;i++){
			int y = in.nextInt();
			a[i]=y;
			//System.out.print(a[i]);
		}
		int z = in.nextInt();
		for(int i=0;i<a.length;i++){
			if(a[i]==z){
				b=i+1;
				break;
			}
		}
		System.out.println(b);
	}
}

Python :

n = int(input())
li = list(map(int,input().split()))
m = int(input())
if m in li:
        print(li.index(m)+1)
else:
        print(-1)