#pragma GCC optimize("O2,O3,Ofast,inline,unroll-loops")
#pragma GCC target("avx2,sse4")
#include <bits/stdc++.h>
#define il inline
#define B __int128
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
il B read(){
    B x=0,c=getchar();
    while(!isdigit(c)) c=getchar();
    while(isdigit(c)) x=x*10+c-48,c=getchar();
    return x;
}
void write(B x){
    if(x<0){putchar('-'),write(-x);return ;}
    if(x>9) write(x/10);
    putchar(x%10+48);
}
il void print(B x,char c){write(x),putchar(c);}
typedef long long ll;
const int mod[101]={0,998244353,998244389,998244391,998244397,998244407,998244431,998244433,998244473,998244487,998244493,998244521,998244523,998244529,998244601,998244617,998244619,998244631,998244649,998244673,998244677,998244679,998244707,998244713,998244749,998244761,998244787,998244799,998244803,998244839,998244853,998244889,998244893,998244899,998244911,998244943,998244967,998244991,998245037,998245063,998245091,998245097,998245099,998245109,998245111,998245141,998245147,998245153,998245159,998245169,998245177,998245189,998245207,998245211,998245223,998245247,998245331,998245349,998245373,998245403,998245463,998245481,998245483,998245487,998245489,998245531,998245543,998245553,998245571,998245613,998245631,998245639,998245687,998245697,998245709,998245711,998245733,998245739,998245757,998245777,998245799,998245837,998245867,998245877,998245909,998245943,998245949,998245981,998246021,998246047,998246071,998246077,998246101,998246129,998246143,998246177,998246189,998246191,998246237,998246251,998246257};
il int qp(int a,int b,int mod){
    int ans=1;
    while(b){
        if(b&1) ans=(1ll*ans*a)%mod;
        a=(1ll*a*a)%mod,b>>=1;
    }return ans;
}
il int INV(int a,int p){return qp(a,p-2,p);}
const int N=3e5+5,M=2005,K=1e5,U=100;
int n,m,p[M],vis[M],cnt,b[N],k1,k2,sum;B a[N];pii ans[N*15];
bitset<M> cc[M];
il void init(){
    for(int i=2;i<M;++i){
        if(!vis[i]) p[++cnt]=i;
        for(int j=1;j<=cnt && i*p[j]<M;++j){
            vis[i*p[j]]=1;
            if(i%p[j]==0) break;
        }
    }
    for(int i=2;i<=cnt;++i) b[++k1]=p[i];
    sort(b+1,b+1+k1);k1=100,k2=100;
    for(int i=1;i<=k1;++i)
        for(int j=0;j<b[i];++j) cc[i][(j*j)%b[i]]=1;
    for(int i=1;i<=k2;++i) b[k1+i]=mod[i];
}
il int CHECK(int p,int v){
    if(p<=k1) return cc[p][v];
    else return (!v) || qp(v,(mod[p-k1]-1)/2,mod[p-k1])==1;
}
bitset<N> t[205];int s[205][N];
int x,y,z;ll u,v,w;
int main(){
    //freopen("a1.in","r",stdin);
    //freopen("a1.out","w",stdout);
    scanf("%d",&n);init();
    for(int i=1;i<=n;++i) a[i]=read();
    for(int j=1;j<=k1+k2;++j){
        //if(j<=10) printf("%d:",b[j]);
        s[j][0]=0,t[j][0]=0,w=1ll*b[j]*b[j];
        for(int i=1;i<=n;++i){
            while(a[i]%w==0) a[i]/=w;
            s[j][i]=(a[i]%b[j]==0),t[j][i]=1-CHECK(j,a[i]%b[j]);
            s[j][i]+=s[j][i-1];
            if(t[j][i]==t[j][i-1]) t[j][i]=0;
            else t[j][i]=1;
            //if(j<=10) cout<<t[j][i];
        }//if(j<=10)puts("");
    }
    for(int i=0;i<n;++i)
        for(int j=i+1;j<=n;++j){
            x=1;
            for(int l=1;l<=k1+k2;++l) if(t[l][i]!=t[l][j] && s[l][j]==s[l][i]){x=0;break;}
            if(x) ++sum,ans[++m]={i+1,j};
        }
    printf("%d\n",sum);
    sort(ans+1,ans+1+m);
    for(int i=1;i<=min(m,K);++i) printf("%d %d\n",ans[i].fi,ans[i].se);
    return 0;
}
/*
il int gggg(int x){
    for(int i=2;i*i<=x;++i) if(x%i==0) return 0;
    return 1;
}
freopen("a111.out","w",stdout);int ccc=0;
for(int i=998244353;i<=998244354+10000;++i){
        if(ccc>=100) break;
        if(gggg(i)) printf("%d,",i),++ccc;
}

3:0100010000
5:0110010101
7:0010100100
11:0100110001
13:0100110001
17:0010100100
19:0110010101
23:0000000000
29:0110010101
31:0010100100

0111100000
0100011001
0011000111
0111011110
0111011110
0011000111
0100011001
0000000000
0100011001
0011000111
*/