Modern art

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

#define LOOP(i,s,e) for (int64_t i = (s); i < (e); i++)
#define SCAN(...) if (scanf(__VA_ARGS__) == 0) return EXIT_FAILURE

int main() {
    uint64_t A = 0, P = 0;
    SCAN("%ld %ld", &A, &P);
    if (P%2 == 1){
        printf("IMPOSSIBLE\n");
        exit(EXIT_SUCCESS);
    }
    P = P/2;
    if (A < P-1){
        printf("IMPOSSIBLE\n");
        exit(EXIT_SUCCESS);
    }
    if (A > (P/2)*(P/2 + P%2)){
        printf("IMPOSSIBLE\n");
        exit(EXIT_SUCCESS);
    }
    int l = P/2;
    int h = P/2+P%2;
    // printf("l:%d, h:%d", l, h);
    int acc = A - P+1;
    printf("POSSIBLE\n");
    // 000000
    LOOP(i,0,h+2)
        printf("0");
    // 01111110
    printf("\n0");
    LOOP(i,0,h)
        printf("1");
    printf("0\n");
    // 01111110
    // 01110000
    // 01000000
    // 01000000
    LOOP(i,0,l-1){
        printf("0");
        printf("1");
        LOOP(j, 0, h-1){
            if (acc > 0){
                printf("1");
                acc--;
            } else {
                printf("0");
            }
        }
        printf("0\n");
    }
    LOOP(i,0,h+2)
        printf("0");
    printf("\n");


    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

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED