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hello, I need some help here, I dunno where's the mistake of my code, i keep getting WA.
pls help :)

#include <cstdio>
#include <iostream>
#include <math.h>

using namespace std;

int main()
{
long long arr[3001];
int n;
while(scanf("%d",&n)!=EOF)
{
bool jolly=true;
bool used[3001];
for(int ...