#include<bits/stdc++.h>
#define int long long
#define I_love_ch ios::sync_with_stdio(0)
#define China cin.tie(0)
#define France cout.tie(0)
#define ch_France return 0
using namespace std;
int n,m,ans=0;
signed main(){
	I_love_ch;
	China;
	France;
	cin>>n>>m;
	if(m==2){
		for(int i=31;i>=0;i--){
			if((1ll<<i)<=n){
				int j=(1ll<<i);
				cout<<((n-j)<<1)+1<<"\n";
				break;
			}
		}
		ch_France;
	}
	for(int i=1;i<=n;i++){
		ans=(ans+m)%i;
	}
	cout<<ans+1<<"\n";
	ch_France;
}