Help me in solving CAESAR problem.....why am i getting RE in one of test case

help
,
1

My issue

My code

#include <bits/stdc++.h>
using namespace std;

int main()
{
    
    int t;
    cin>>t;
    
    while(t--)
    {
        int n;
        cin>>n;
     int arr[n];
   string s1,s2,s3,s4;
   cin>>s1>>s2>>s3;
   
   int store1=s1[0];
   int store2=s2[0];
   int store3=store2-store1;
   
   for(int i=0;i<n;i++)
   {
       arr[i]=s3[i];
   }

   for(int i=0;i<n;i++)
   {
       if((arr[i]+store3)<=122 && (arr[i]+store3)>=97)
       s4[i]=char(arr[i]+store3);
       
       else if((arr[i]+store3)<97)
        s4[i]=char(arr[i]+store3+26);
       
       else
       s4[i]=char(arr[i]+store3-26);
   }
   
    for(int i=0;i<n;i++)
   {
       cout<<s4[i];
   }
   
   cout<<endl;
    }
   

    return 0;
}

Problem Link: CAESAR Problem - CodeChef