#include using namespace std; string s; int st, cnt = 0, a[1000005], ans[1000005]; int main() { cin >> s >> st; for (int i = 0; i < s.size(); i++) { a[i] = s[i] - 'A' + st; } for (int i = s.size() - 1; i >= 0; i--) { while (a[i] > 0) { ans[++cnt] = a[i] % 10; a[i] /= 10; } } for (int i = cnt - 1; i >= 3; i--) { for (int j = 1; j <= i; j++) { ans[j] = (ans[j] + ans[j + 1]) % 10; } } if (ans[3] == 1 && ans[2] == 0 && ans[1] == 0) { cout << 100 << endl; } else if ((ans[2] + ans[3]) % 10) { cout << (ans[2] + ans[3]) % 10 << (ans[1] + ans[2]) % 10 << endl; } else { cout << (ans[1] + ans[2]) % 10 << endl; } return 0; }