// you can also use imports, for example:

// import java.util.*;

// you can write to stdout for debugging purposes, e.g.

// System.out.println("this is a debug message");

class Solution {

public int solution(int X, int[] A) {

// count==x for a path

Boolean[] fall=new Boolean[X];

for(int i=0; i<X; i++){

fall[i]=false;

}

int count=0;

int ans=-1;

//checking the path

for(int j=0;j<A.length;j++){

if(fall[A[j]-1]==false){

fall[A[j]-1]=true;

++count;

if(count==X){

ans=j;

break;

}

}

}

return ans;

}

public static void main(String[] args){

Solution sol=new Solution();

int X=5;

int[] A={1,3,1,4,2,3,5,4};

System.out.println(sol.solution(X, A));

}

}