swap first and last digits of number

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

int main(){
    int a, num, count=0, first_digit, last_digit;
    printf("Enter the number: ");
    scanf("%d", &num);
    a=num;
    while(a!=0){
        a /= 10;
        count++;
    }
    last_digit=num%10;
    first_digit=num/(int)pow(10, (count-1));

    num=num-(first_digit*(int)pow(10, count-1));
    num=(num-(last_digit))/10;

    if(count==2){
        printf("%d", last_digit);
        printf("%d", first_digit);
    }
    else{
        printf("%d", last_digit);
        printf("%d", num);
        printf("%d", first_digit);
    }
}