#include<stdio.h>

#include<iostream>

#include<memory.h>

#include<math.h>

using namespace std;

int flag1[];

int flag2[];

int flag3[];

int main()

{

    memset(flag1,,sizeof(flag1));

    memset(flag2,,sizeof(flag2));

    memset(flag3,,sizeof(flag3));

    int n;

    cin>>n;

    int kiss,kiss1=,kiss2=,kiss3=;

    int minn=;

    for(int i=;i<n;i++)

    {

        cin>>kiss;

        if(kiss==)

            flag1[++kiss1]=i;

        else if(kiss==)

            flag2[++kiss2]=i;

        else

            flag3[++kiss3]=i;

    }

    minn=min(kiss1,min(kiss2,kiss3));

    cout<<minn<<endl;

    for(int i=;i<minn;i++)

    {

        cout<<flag1[i+]+<<" "<<flag2[i+]+<<" "<<flag3[i+]+<<endl;

    }

    return ;

}