#include<bits/stdc++.h>
#define N 500010
#define LL long long
#define rep(i,l,r) for(int i=l;i<=r;i++)
using namespace std;
int rd() {
	int res=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9') {if(ch=='-') f*=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') res=(res<<1)+(res<<3)+(ch^48),ch=getchar();
	return res*f;
}
int T,n,a[N];
int gets(int A,int B) {
	if(A<B) swap(A,B);
	int res=0,up=0;
	while(A&&B) {
		if((A%10)+(B%10)+up>=10) up=1,res++;
		else up=0;
		A/=10,B/=10;
	}
	while(A%10==9&&up) res++,A/=10;
	return res;
}
int main() {
	T=rd();
	while(T--) {
		n=rd();
		rep(i,1,n) a[i]=rd();
		int ans=0;LL now=a[1];
		rep(i,2,n) ans+=gets(now,a[i]),now+=a[i];
		printf("%d\n",ans);
	}
	return 0;
}