#include<stdio.h>
int main() {
    long long n;
    
    if (scanf("%lld", &n) != 1) {
        printf("Invalid Input");
        return 0;
    }
    
    if (n < 1) {
        printf("Invalid Input");
        return 0;
    }
    
    char result[120];
    int index = 0;
    
    while (n > 0) {
        long long rem = (n - 1) % 26;
        result[index++] = 'A' + rem;
        n = (n - 1) / 26;
    }
    
    result[index] = '\0';
    
    for (int i = 0; i < index / 2; i++) {
        char temp = result[i];
        result[i] = result[index - i - 1];
        result[index - i - 1] = temp;
    }
    
    printf("%s, result");
    return 0;
}