#include<bits/stdc++.h>
using namespace std;
#define int long long
#define f(i,j,k) for(int i=j;i<=k;++i)
#define g(i,j,k) for(int i=j;i>=k;--i)
int n,m,s,l;
const int N=3e6,k=8;
bool f[9][9][9][9][9][9][9][7];
inline void ycl(){
	f[0][0][0][0][0][0][0][0]=1;
	f(a0,0,k)f(a1,0,k)f(a2,0,k)f(a3,0,k)f(a4,0,k)f(a5,0,k)f(a6,0,k)f(c,0,6)if(f[a0][a1][a2][a3][a4][a5][a6][c]){
		if(a0<k)f[a0+1][a1][a2][a3][a4][a5][a6][(c*10+0)%7]=1;
		if(a1<k)f[a0][a1+1][a2][a3][a4][a5][a6][(c*10+1)%7]=1;
		if(a2<k)f[a0][a1][a2+1][a3][a4][a5][a6][(c*10+2)%7]=1;
		if(a3<k)f[a0][a1][a2][a3+1][a4][a5][a6][(c*10+3)%7]=1;
		if(a4<k)f[a0][a1][a2][a3][a4+1][a5][a6][(c*10+4)%7]=1;
		if(a5<k)f[a0][a1][a2][a3][a4][a5+1][a6][(c*10+5)%7]=1;
		if(a6<k)f[a0][a1][a2][a3][a4][a5][a6+1][(c*10+6)%7]=1;
	}
}
int a[N],b[N],c[N],d[N],p[N],q[N];
int ck(int n,int p){
	if(!n)return 1;
	f(i,0,6)if(c[i]){
		--c[i];
		int q=(p-i+7)*5%7;d[n]=i;
		if(f[c[0]][c[1]][c[2]][c[3]][c[4]][c[5]][c[6]][q])return ck(n-1,q);
		++c[i];
	}
	return 0;
}
inline void doing(){
	f(i,0,6)b[i]=0;n=m=0;
	f(i,0,9)cin>>a[i],b[i%7]+=a[i];
	f(i,0,6)for(m+=c[i]=b[i]%6;c[i]+6<=min(k,b[i]);c[i]+=6)m+=6;
	if(!ck(m,0))return printf("-1\n"),void();
	f(i,1,m)f(c,0,9)if(c%7==d[i]&&a[c]){
		p[++n]=1;--a[q[n]=c];break;
	}
	f(i,0,6)f(c,0,9)if(c%7==i&&a[c])p[++n]=a[c],q[n]=c;
	printf("%lld\n",n);
	f(i,1,n)printf("%lld %lld\n",p[i],q[i]);
}
signed main(){
	ycl();
	int t;
	cin>>t;
	while(t--)doing();
	return 0;
}