Decrypt

#include <iostream>
#include <string>
using namespace std;
int main(){

	cin.sync_with_stdio(false);
	
	char f[26];
	int k;
	string S;
	for (int i=0;i<26;i++){
		cin>>f[i];
	}
	cin>>k;
	cin>>S;
	char invf[26];
	for(int i=0;i<26;i++){
		invf[i]=-1;
	}
	char fin[26];
	for(int i=0;i<26;i++){
		if(invf[int(f[i]-'a')]!=-1){
			cout<<"impossible"<<endl;
			return 0;
		}
		invf[int(f[i]-'a')]=(char)i+'a';
	}
	
	for(int i=0;i<26;i++){
		char c='a'+i;
		char c0=c;
		int g=k;
		for(int j=0;j<g;j++){
			c=invf[c-'a'];
			if(c0==c){
				g%=j+1;
				j=-1;
				c='a'+i;
			}
		}
		fin[i]=c;
	}
	
	for(unsigned int j=0;j<S.size();j++){
		S[j]=fin[S[j]-'a'];
	}
	
	cout << S << endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED