Split in Three

input/code.cpp: In function 'int main()':
input/code.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i",&n);
     ~~~~~^~~~~~~~~

#include<bits/stdc++.h>
using namespace std;

const int nmax=100+5;

void no()
{
    printf("IMPOSSIBLE\n");
}

int n;

int outp[nmax];

void go(int start)
{
    while(start<=n)
    {
        outp[start]=1;
        outp[start+5]=1;

        outp[start+1]=2;
        outp[start+4]=2;

        outp[start+2]=3;
        outp[start+3]=3;

        start+=6;
    }

    for(int i=1;i<=n;i++)
        printf("%i ",outp[i]);
}
int main()
{
    scanf("%i",&n);

    if(n%3==1)no();

    if(n%6==0)
    {
        outp[6]=1;
        outp[1]=2;
        outp[2]=2;
        outp[4]=2;
        outp[3]=3;
        outp[5]=3;

        go(7);
    }
    if(n%6==2)
    {
        outp[1]=2;
        outp[2]=3;

        go(3);
    }

    if(n%6==3)
    {
        outp[1]=1;
        outp[2]=2;
        outp[3]=3;

        go(4);
    }

    if(n%6==5)
    {
        outp[1]=3;
        outp[2]=3;
        outp[3]=3;
        outp[4]=1;
        outp[5]=2;

        go(6);
    }

    return 0;
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: ACCEPTED

Test 8

Group: 1, 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 2

Verdict: ACCEPTED