#include<bits/stdc++.h>
#define MOD 1000000007
#define pb push_back
#define ll long long
using namespace std;
int main()
{
std::ios_base::sync_with_stdio(0);
int t;
cin >> t;
while (t--)
{
int n;
cin >> n;
vector<string> a(n);
for (int i=0; i<n; ++i) cin >> a[i];
int res=MOD;
for (int i=1; i<n; ++i)
{
int m=a[0].size();
int dp[m+1][a[i].size()+1];
for (int j=0; j<=m; ++j) dp[j][0]=0;
for (int j=0; j<=a[i].size(); ++j) dp[0][j]=0;
string tmp;
for (int j=1; j<=m; ++j)
{
for (int k=1; k<=a[i].size(); ++k)
{
if (a[0][j-1]==a[i][k-1])
{
dp[j][k]=dp[j-1][k-1]+1;
char c=a[0][j-1];
tmp+=c;
}
else dp[j][k]=max(dp[j-1][k], dp[j][k-1]);
}
}
if (dp[m][a[i].size()]<res) res=dp[m][a[i].size()];
a[0]=tmp;
}
cout << res << "\n";
}
}
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