#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 1000000007
#define MAX_N 5001
#define EPS 1e-10

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<string, ll> PS;
typedef vector<ll> V;

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 1000000007

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<double, double> PD;
typedef pair<string, ll> PS;
typedef vector<ll> V;

int n;
string s, ans;

int gcd(int a, int b){
	if (b == 0)return false;

	if (b == 1)return true;

	return gcd(b, a%b);
}

int main(){
	cin >> n;
	cin.ignore();
	REP(i, n){
		getline(cin, s);
		bool f = 0;
		for (int j = 1; j < 26; j++){
			if (!gcd(26, j))continue;
			for (int k = 0; k < 26; k++){
				//cout << j << " " << k << endl;
				REP(l, s.size()){
					if (s[l]<'a' || s[l]>'z'){
						ans += s[l];
						continue;
					}
					ans += (j*(s[l] - 'a') + k) % 26 + 'a';
				}
				if (ans.find("this") != -1
					|| ans.find("that") != -1)f = 1;
				if (f)break;
				ans.clear();
			}
			if (f)break;
		}

		cout << ans << endl;
	}
}