#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
using namespace std;
typedef __int128 L;
typedef unsigned long long ull;
const int N=3e5+5,M=1e5+5;
int n,num; L a[N];
ull b[N],ans; bool vis[M],ok[M];
__gnu_pbds::gp_hash_table<ull,int> id;
vector<int> vec[N]; mt19937 rnd(time(0));
inline void read(L &ret){
	ret=0; int ch=getchar();
	while(!isdigit(ch)) ch=getchar();
	while(isdigit(ch))
		ret=ret*10+(ch^48),ch=getchar();
}
int main(){
	cin>>n,vis[1]=1;
	for(int i=1;i<=n;++i) read(a[i]);
	for(int i=2;i<M;++i){
		if(vis[i]) continue;
		for(int j=i*2;j<M;j+=i) vis[j]=1;
	}
	for(int t=0,p;t<38;++t){
		while(1){
			p=rnd()%(M-1)+1;
			if(!vis[p]) break;
		}
		memset(ok,0,sizeof(ok));
		for(int i=1;i<=(p+1)/2;++i) ok[1ll*i*i%p]=1;
		for(int i=1,s=0;i<=n;++i){
			L x=a[i]; while(x%p==0) x/=p;
			s^=!ok[x%p],b[i]^=s*(1ull<<t);
		}
	}
	for(int i=0;i<=n;++i){
		if(!id[b[i]]) id[b[i]]=++num;
		vec[id[b[i]]].emplace_back(i);
	}
	for(int i=1;i<=num;++i)
		ans+=1ll*vec[i].size()*(vec[i].size()-1)/2;
	cout<<ans<<endl,ans=min(ans,100000ull);
	for(int l=1;l<=n&&ans;++l){
		int x=id[b[l-1]];
		for(int r:vec[x])
			if(l<=r){
				printf("%d %d\n",l,r);
				if(!(--ans)) break;
			}
	}
	return 0;
}