#include<iostream>
using namespace std;
#include<cstdio>
#include<cstring>
#include<string>
struct node
{
long d;
node * next;
} ;
long n,m;
node * head,* p,* r;
int main()
{
long i,j;
cin>>n>>m;
head=(node*)malloc(sizeof(node));
head->d=1;
head->next=NULL;
r=head;
for(i=2;i<=n;i++)
{
p=(node*)malloc(sizeof(node));
p->d=i;
p->next=NULL;
r->next=p;
r=p;
}
r->next=head;
r=head;
for (i=1;i<=n;i++)
{
for(j=1;j<=m-2;j++) r=r->next;
r->next=r->next->next;
r=r->next;
}
cout<<r->d<<endl;
return 0;
}