solution

#include <stdio.h>
#include <stdlib.h>     /* srand, rand */
#include <time.h>       /* time */
#include <iostream>
using namespace std;

const int MAXN = int(1e4);
const int MAXN_PLUS = MAXN + 15;

int seq[MAXN_PLUS];
int n;

void shuffle() {
    for(int i = 0; i < n; i++) {
        int swapWith = rand()%n;
        swap(seq[i], seq[swapWith]);
    }
}

int randomSolve(int k) {
    for(int j = 0; j < k; j++) {
        int s = 0;
        for(int i = 0; i < n; i++) {
            s = (s + seq[i])%n;
            if (s == 0) {
                return i + 1;
            }
        }
        shuffle();
    }
    return 0;
}

void printAnsw(int len) {
    if (len) {
        printf("%d\n", len);
        for(int i = 0; i < len; i++) {
            printf("%d\n", seq[i]);
        }
    }else {
        printf("0\n");
    }
}

int main() {
    scanf("%d", &n);
    int answInd = -1;
    for(int i = 0; i < n; i++) {
        scanf("%d", &seq[i]);
        if (seq[i] % n == 0) {
            answInd = i;
        }
    }
    if (answInd > -1) {
        printf("1\n%d\n", seq[answInd]);
        return 0;
    }else {
        int len = randomSolve(40000);
        printAnsw(len);
    }
    return 0;
}