n = str(abs(int(input()))) print(int(n[:1]) + int(n[int(len(n)-1):]))

include <iostream>

include <cmath>

using namespace std;

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

int first_digit = abs(n) % 10;
int last_digit = abs(n);
while (last_digit >= 10) {
    last_digit /= 10;
}

int sum = first_digit + last_digit;

cout << sum << endl;

return 0;

}