#include<stdio.h>
#include<stdlib.h>
#include<string.h>
void numberToExcelTitle(int n)
{
    if(n<=0)
    {
        return;
    }
    char result[100];
    int index = 0;
    while (n > 0)
    {
        n--;
        int rem = n % 26;
        result[index++] = 'A'+ rem;
        n /= 26;
    }
    title[index]='\0';
    for(int i=index-1;i>=0;i--)
    {
        putchar('\n');
    }
    int main()
    {
        int n;
        if(scanf("%d", &n)<=0)
        {
            printf("Invalid input");
            return 1;
        }
        if(n<=0)
        {
            printf("-1");
            return 1;
        }
        numberToExcelTitle(n);
        return 0;
    }