#include<bits/stdc++.h>
#define poly vector<int>
#define IOS ios::sync_with_stdio(false)
#define ull unsigned long long
#define ll long long
#define mp make_pair
#define mt make_tuple
#define pa pair < int,int >
#define fi first
#define se second
#define inf 1e18
#define sz(x) ((int)((x).size()))
#define int ll
// #define N 
using namespace std;
const ull B=10007;
const int N=300005,Lim=N-5;
ull all[N];
bool vis[N];
int val[N];
int pr[N],cnt;
int n;
__int128 a[N];
mt19937_64 rnd(time(0));
inline int rndd(int l,int r)
{
    return rnd()%(r-l+1)+l;
}
inline ll quickPower(ll x,ll y,ll mod)
{
    ll res=1;
    while (y)
    {
        if (y&1) res=res*x%mod;
        x=x*x%mod;
        y>>=1;
    }
    return res;
}
void BellaKira()
{
    vis[1]=1;
    for (int i=2;i<=Lim;i++)
        if (!vis[i])
        {
            pr[++cnt]=i;
            for (int j=i+i;j<=Lim;j+=i) vis[j]=1;
        }
    cin>>n;
    for (int i=1;i<=n;i++)
    {
        string st;
        cin>>st;
        for (auto u:st)
            a[i]=a[i]*10+u-'0';
    }
    // return;
    for (int tms=1;tms<=45;tms++)
    {
        int mod;
        while (1)
        {
            mod=rndd(Lim-100000,Lim);
            if (!vis[mod]) break;
        }
        // cout<<"!!"<<mod<<endl;
        val[1]=1;
        for (int i=2;i<mod;i++)
        {
            if (!vis[i])
            {
                val[i]=quickPower(i,(mod-1)/2,mod);
            }
            for (int j=1;j<=cnt&&pr[j]<=i&&pr[j]*i<mod;j++)
            {
                val[pr[j]*i]=val[i]*val[pr[j]]%mod;
                if (i%pr[j]==0) break;
            }
        }
        int zs=0;
        for (int i=0,t=1;i<=n;i++)
        {
            all[i]=all[i]*B+val[t];
            all[i]=all[i]*B+zs%2;
            if (i==n) break;
            __int128 nw=a[i+1];
            while (nw%mod==0) zs++,nw/=mod;
            t=t*(nw%mod)%mod;
        }
    }
    unordered_map<ull,poly>G;
    for (int i=n;i>=0;i--) 
        G[all[i]].push_back(i);
    int ans=0;
    for (auto [u,v]:G)
        ans=(ans+sz(v)*(sz(v)-1)/2);
    cout<<ans<<'\n';
    ans=min(ans,100000ll);
    for (int i=0;i<n;i++)
    {
        G[all[i]].pop_back();
        for (int j=sz(G[all[i]])-1;j>=0;j--)
        {
            if (ans) cout<<i+1<<" "<<G[all[i]][j]<<"\n";
            else return;
            ans--;
        }
    }
}
signed main()
{
    // freopen("1.in","r",stdin);
    // freopen("1.out","w",stdout);
    IOS;
    cin.tie(0);
    int T=1;
    while (T--)
    {
        BellaKira();
    }
}
/*list:
1.mod 998244353 or 1e9+7 or ???
2.N
3.duipai shuju xingtai duoyidian
...
*/