WA in DECSTR

                    #include<iostream>
                #include<vector>

                using namespace std;

                int main(){
                   std::ios_base::sync_with_stdio(false);
                vector <long int> v;
                int t1,x,t;
                cin>>t1;
                for(int i=0;i<t1;i++)
                {
                 cin>>x;
                 v.push_back(x);
                }


                for(int i=0;i<t1;i++)
                {

                        t=v.at(i)%25;


                 for(int j=t;j>=0;j--)
                 {
                    cout<<static_cast<char>('a'+j);
                 }


                for(int l=0;l< static_cast<int>(v.at(i)/25);l++)
                    cout<<"zyxwvutsrqponmlkjihgfedcba";



                 cout<<endl;



                }


                return 0;
                }

I'm getting WA, any hopes?