Language: C++

#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define ll long long 
#define FI first 
#define SE second
#define pb push_back 
#define eb emplace_back
#define mod 1000000007
#define all(c) (c).begin(),(c).end()
#define LB  lower_bound
#define UB  upper_bound
#define max3(a,b,c) max(c,max(a,b))
#define min3(a,b,c) min(c,min(a,b))
#define mems(s, n) memset(s, n, sizeof(s))
#define NINF -1e18
#define INF 1e18
#define int ll int
#define double long double
#define OOK order_of_key  //no of elements less than
#define FBO find_by_order //iterator pointing kth element;indexing starts from 0
#define CK3(x,y,z) cout<<(x)<<" "<<(y)<<" "<<(z)<<endl
#define CK4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<endl

typedef pair<int,int> PII;
typedef pair<pair<int,int>,int> PPII;
typedef pair<int,pair<int,int>> PIPI;
typedef map<int,int>MII;
typedef vector<int> VI;
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

int power(int a, int b)
{int x=1,y=a;while(b>0){if(b%2){x =(x*y);}y =(y*y);b/=2;}return x
;}



signed main()
{
ios::sync_with_stdio(false); cin.tie(0);
int T=1,T1=0;//cin>>T;
while(T1++<T)
{//cout<<"Case #"<<T1<<": ";
   int n;
   cin>>n;string s="";
  while(n>0)
  {
   char ch='a'+(n-1)%26;
   s=ch+s;
   if(n%26==0)n--;
   n/=26;
  }
   cout<<s<<endl;
}


return 0;
}



#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define ll long long 
#define FI first 
#define SE second
#define pb push_back 
#define eb emplace_back
#define mod 1000000007
#define all(c) (c).begin(),(c).end()
#define LB  lower_bound
#define UB  upper_bound
#define max3(a,b,c) max(c,max(a,b))
#define min3(a,b,c) min(c,min(a,b))
#define mems(s, n) memset(s, n, sizeof(s))
#define NINF -1e18
#define INF 1e18
#define int ll int
#define double long double
#define OOK order_of_key  //no of elements less than
#define FBO find_by_order //iterator pointing kth element;indexing starts from 0
#define CK3(x,y,z) cout<<(x)<<" "<<(y)<<" "<<(z)<<endl
#define CK4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<endl

typedef pair<int,int> PII;
typedef pair<pair<int,int>,int> PPII;
typedef pair<int,pair<int,int>> PIPI;
typedef map<int,int>MII;
typedef vector<int> VI;
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

int power(int a, int b)
{int x=1,y=a;while(b>0){if(b%2){x =(x*y);}y =(y*y);b/=2;}return x
;}



signed main()
{
ios::sync_with_stdio(false); cin.tie(0);
int T=1,T1=0;//cin>>T;
while(T1++<T)
{//cout<<"Case #"<<T1<<": ";
   int n;
   cin>>n;string s="";
  while(n>0)
  {
   char ch='a'+(n-1)%26;
   s=ch+s;
   if(n%26==0)n--;
   n/=26;
  }
   cout<<s<<endl;
}


return 0;
}





Compiler output:
a.cc:99:5: error: redefinition of 'long long int power(long long int, long long int)'
   99 | int power(int a, int b)
      |     ^~~~~
a.cc:35:5: note: 'long long int power(long long int, long long int)' previously defined here
   35 | int power(int a, int b)
      |     ^~~~~
a.cc:105:8: error: redefinition of 'int main()'
  105 | signed main()
      |        ^~~~
a.cc:41:8: note: 'int main()' previously defined here
   41 | signed main()
      |        ^~~~