#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;
vector<int>c(7);
map<vector<int>,int>f[7];
int a[N],b[N],p[N],q[N];
int dfs(int n,int k){
	if(!n)return!k+1;
	if(f[k][c])return f[k][c];
	f(i,0,6)if(c[i]){
		--c[i];
		int p=dfs(n-1,(k-i+7)*5%7);
		++c[i];
		if(p>1)return b[n]=i,f[k][c]=2;
	}
	return f[k][c]=1;
}
inline void doing(){
	f(i,0,6)b[i]=0;n=m=s=0;
	f(i,0,9)cin>>a[i],b[i%7]+=a[i];
	f(i,0,6)s+=!!b[i];s=s>3?7:30;
	f(i,0,6)for(m+=c[i]=b[i]%6;c[i]+6<=min(s,b[i]);c[i]+=6)m+=6;
	if(dfs(m,0)<2)return puts("-1"),void();
	f(i,1,m)f(c,0,9)if(c%7==b[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(){
	int t;
	cin>>t;
	while(t--)doing();
	return 0;
}