/*******************************************************
 Program to convert a decimal number to an octal number
 ******************************************************/

#include<stdio.h> // include stdio.h library
#include<math.h> // include math.h library

int main(void)
{   
    long long num, oct = 0;    
    int i = 0, rem;

    printf("Enter a decimal number: \n");
    scanf("%lld", &num);      

    while(num != 0)
    {
        rem = num % 8;  // get the last digit
        oct = rem * (long long)pow(10, i++) + oct;  
        num /= 8;  // get the quotient
    }

    printf("0o");

    printf("%lld", oct);        

    return 0; // return 0 to operating system
}