#include <iostream>
using namespace std;

int main() {
    int num;
    cin >> num;

    int original_num = num;
    int new_num = 0;

    while (num > 0) {
        new_num = new_num * 10 + num % 10;
        num /= 10;
    }

    int difference = original_num - new_num;
    cout << difference << endl;

    return 0;
}    
/**************************************************************
	Problem: 1702
	User: linzihang
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/