#include <iostream>


using namespace std;

typedef unsigned long long ll;

ll cnt;
ll res;

ll joseph(ll n, ll k) {
    if (n == 1) return 0;
    if (k == 1) return n - 1;
    if (k > n) return (joseph(n - 1, k) + k) % n;
    cnt = n / k;
    res = joseph(n - cnt, k);
    if (res < n % k) {
        res += n;
        res -= n % k;
    } else {
        res -= n % k;
        res += res / (k - 1);
    }
    return res;
}


int main() {
    int n, k;
    cin >> n >> k;
    std::cout << joseph(n, k) + 1 << std::endl;
    return 0;
}