C++ :

#include <iostream>
using namespace std;
int main() {
    int num, reversedNum = 0;
    cin >> num;
    do {
        int digit = num % 10;
        reversedNum = reversedNum * 10 + digit;
        num /= 10;
    } while (num != 0);
    cout << reversedNum;
    return 0;
}