#include<bits/stdc++.h>

using namespace std;
int n;
int a[1000006];
int A[10],last[10];
int op,b[10][1000005];
int u[1000005],v[1000005],w[1000005],cnt2;
int id[1000005];
bool Solve(int x,int y){
    bool pd=false;cnt2=0;//cerr<<x<<' '<<y<<endl;
    if(x+y>min({A[2],A[1],A[3]}))return true;
    for(int j=1;j<=x;j++){
        int X=A[3]-x+j;//cerr<<x<<" "<<y<<" "<<b[1][j] <<" "<<b[3][X]<<endl;
        if(b[1][j]>b[3][X])return true;
        u[++cnt2]=b[1][j],v[cnt2]=b[3][X];
    }
    for(int j=1;j<=y;j++){
        int X=A[1]-y+j;
        if(b[3][j]>b[1][X])return true;
        u[++cnt2]=b[3][j],v[cnt2]=b[1][X];
    }
    // cerr<<x<<" "<<y<<" "<<pd<<endl;
    return false;
}
bool cmp(int x,int y){
    return v[x]<v[y];
}
int lans[600005][3],now[600005][3];
bool check(){
    for(int i=1;i<=cnt2;i++)id[i]=i;
    sort(id+1,id+1+cnt2,cmp);
    set<int>st;
    for(int i=1;i<=A[2];i++)st.insert(b[2][i]);
    for(int i=1;i<=cnt2;i++){
        auto it=st.lower_bound(u[id[i]]);
        // cerr<<u[id[i]] <<" "<<v[id[i]]<<endl;
        if(it==st.end()||*it>v[id[i]])return false;
        lans[i][0]=u[id[i]];
        lans[i][1]=*it;
        lans[i][2]=v[id[i]];
        st.erase(it);
    }
    return true;
}
int cnt[600005][4];
int main(){
    // freopen("triples.in","r",stdin);
    // freopen("triples.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]),A[a[i]]++,b[a[i]][A[a[i]]]=i;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=3;j++)cnt[i][j]=cnt[i-1][j];
        cnt[i][a[i]]++;
    }
    int last=0,lima=n,limb=n,limab;
    for(int i=1;i<=n;i++){
        lima=min(lima,last+cnt[i][2]-cnt[i][3]+A[3]);
        last=min(last,cnt[i][1]-cnt[i][2]);
    }
    last=0;
    for(int i=1;i<=n;i++){
        limb=min(limb,last+cnt[i][2]-cnt[i][1]+A[1]);
        last=min(last,cnt[i][3]-cnt[i][2]);
    }
    last=0;
    for(int i=1;i<=n;i++){
        limab=min(limab,last+cnt[i][2]-cnt[i][1]+A[1]+A[3]-cnt[i][3]);
        last=min(last,cnt[i][1]+cnt[i][3]-cnt[i][2]);
    }
    lima=min(lima,limab);
    limb=min(limb,limab-lima);
    Solve(lima,limb);
    check();
    printf("%d\n",cnt2);
    for(int i=1;i<=cnt2;i++)printf("%d %d %d\n",lans[i][0]-1,lans[i][1]-1,lans[i][2]-1);
    return 0;
}