#include<iostream>
#include<string>
#include<vector>
#include <cstdlib>
#include<cctype>
#include <algorithm>    
using namespace std;
typedef long long ll;
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define REPD(i,n) for(ll i=n-1;i>=0;i--)
#define FOR(i,a,b) for(ll i=a;i<=(ll)(b);i++)
#define FORD(i,a,b) for(ll i=a;i>=(ll)(b);i--)
#define VCOUT(num) for(auto& num:vec)
#define GET_ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
#define LLINF 1000000000000000000//10^18
#define INF 1000000000000 //10^12
#define MOD 1000000007 //10^9+7:合同式の法
#define MAXR 100000
#define MAX 100
#define MX 10

//int main(int argc, char const* argv[]){

int main(){ 
    vector<int>vec;
     vector<char>cvec;
      vector<string>svec;
    
   int a,b,x,y,z,count=0;
   string str1[MX],str2;
   char c='`';
   cin>>a;
   if(a<=26) printf("%c",c+a);
   if((27<=a)&&(a<=702))
   
   
    
  //std::sort(vec.begin(),vec.end());
  //for(auto& num:vec)cout<<num<<endl;
  auto answer=c;
  cout<<answer<<endl;
    return 0;
}

