#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 8e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
mt19937 rd(time(NULL));
ll t,a[11],id[55],tot=0,b[8]={0,1,4,6,5,2},pw[8]={1,3,2,6,4,5};
ll p[22],cnt,nd,q[22],res[22];
bl ck[22],pd;
il bl cmp(ll x,ll y){
	return a[x]<a[y];
}
void dfs(ll now){
	if(now==cnt){
		if(!nd){
			pd=1;
			fr(i,1,cnt) res[i]=q[cnt-i+1];
		}
		return;
	}
	now++;
	fr(i,1,cnt){
		if(ck[i]) continue;
		ck[i]=1;
		nd=(nd+p[i]*pw[(now-1)%6]%7)%7;
		q[now]=p[i];
		dfs(now);
		ck[i]=0;
		nd=(nd-p[i]*pw[(now-1)%6]%7+7)%7;
	}
}
int main(){
	t=read();
	while(t--){
		tot=0;
		fr(i,0,9){
			a[i]=read();
			fr(j,1,min(a[i],4ll)) id[++tot]=i;
		}
		if(tot<4){
			nd=0;
			cnt=tot;
			fr(i,1,tot) p[i]=id[i];
			pd=0;
			dfs(0);
			if(!pd) writeln(-1);
			else{
				writeln(tot);
				fr(i,1,tot) pf("%lld %lld\n",1ll,res[i]);
			}
			continue;
		}
		fr(_,1,100){
			shuffle(id+1,id+tot+1,rd);
			fr(i,1,4) a[id[i]]--;
			ll tmp=pw[4],cntt=0;
			nd=0;
			fr(i,0,9){
				if(!a[i]) continue;
				nd=(nd+b[a[i]%6]*tmp*i%7)%7;
				tmp=tmp*pw[a[i]%6]%7;
				cntt++;
			}
			pd=0;
			cnt=4;
			fr(i,1,cnt) p[i]=id[i];
			dfs(0);
			if(pd){
				writeln(cntt+4);
				pfr(i,9,0) if(a[i]) pf("%lld %lld\n",a[i],i);
				fr(i,1,cnt) pf("%lld %lld\n",1ll,res[i]);
				break;
			}
			fr(i,1,4) a[id[i]]++;
		}
		if(!pd) writeln(-1);
	}
}
/*
3
1 2 3 4 1 2 1 1 0 0
0 0 1 1 1 0 0 1 0 0
0 1 0 2 0 1 0 0 2 0

3
0 0 1 0 5 0 0 1 0 0
0 2 0 0 3 0 6 0 0 0
0 0 0 0 1 0 4 5 0 0

3
0 0 2 0 0 1 0 2 0 0
0 3 0 0 4 0 4 0 0 0
0 0 0 2 0 3 0 0 2 0

3
0 0 3 0 0 2 0 0 0 0
0 4 0 0 3 0 0 0 0 0
0 0 0 5 0 0 0 0 7 0

3
0 1 0 0 1 0 0 0 0 0
0 2 0 0 0 0 1 0 0 1
0 1000000000 0 0 0 0 0 0 0 0

1
1 0 0 1 1 0 0 1 0 0
*/