Counter

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#define LOOP(i,s,e) for (uint64_t i = (s); i < (e); i++)
#define SCAN(...) if (scanf(__VA_ARGS__) == 0) return EXIT_FAILURE

int main() {
    uint64_t x = 0;
    uint64_t tab[11] = {0, 6, 12, 5, 11, 4, 10, 3, 9, 2, 8};
    SCAN("%ld", &x);
    if (x == 0){
        printf("0\n");
        exit(EXIT_SUCCESS);
    }
    if (x < 11){
        printf("-1\n");
        exit(EXIT_SUCCESS);
    }
    uint64_t nb = (x / 11) + tab[x % 11];
    printf("%ld\n", nb);

    // main algo


    return EXIT_SUCCESS;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED