#include <cstdio>
#include <queue>
#include <vector>
#include <algorithm>
using namespace std;
int k, m;
bool vis[1000010];
long long d[1000010];
vector<pair<int, int> > G[1000010];
priority_queue<pair<long long, int> > pq;
void dijkstra() {
    for (int i = 1; i < m; i++) {
        d[i % k] = min(d[i % k], (long long)i);
        pq.push({-d[i % k], i % k});
    }
    while (!pq.empty()) {
        int t = pq.top().second;
        pq.pop();
        if (vis[t]) continue;
        vis[t] = true;
        for (int i = 0; i < G[t].size(); i++) {
            if (d[G[t][i].first] > d[t] + G[t][i].second) {
                d[G[t][i].first] = d[t] + G[t][i].second;
                pq.push({-d[G[t][i].first], G[t][i].first});
            }
        }
    }
}
int main() {
    scanf("%d%d", &k, &m);
    for (int i = 0; i < k; i++) {
        d[i] = 1e18;
        for (int j = 0; j < m; j++) {
            G[i].push_back({(i * m + j) % k, j});
        }
    }
    dijkstra();
    printf("%lld\n", d[0]);
    return 0;
}