#ifdef EZ
   #include "./ez/ez.h"
#else
   #include <bits/stdc++.h>
#endif
#define mp make_pair
#define mt make_tuple
#define ll long long
#define pb emplace_back
#define fi first
#define se second
using namespace std;



int main()
{
   cin.tie(0)->sync_with_stdio(0);
   
   int t;
   cin >> t;
   while (t--)
   {
      string s;
      cin >> s >> s;

      int cnt = 0;
      for (int i = 0; i < s.size()/2; ++i)
         if (s[i] != s[s.size()-i-1])
            cnt+=2;
         else
            break;
      

      cout << s.size()-cnt << '\n';
  
   }
}