#include <iostream>
#include <vector>
#include <stdlib.h>
using namespace std;
int main()
{
int n, m;
// 輸入描述的是最後爲0結束
while ((cin >> n >> m) && !(n == 0 && m == 0))
{
vector<int> vt(n);
for (int i = 0; i < n; i++)
vt[i] = i + 1;
int a = n; // 標記剩下的猴子
int b = 0; // 標記報數m
while (a > 1)
{
for (int i = 0; i < n; i++)
{
if (vt[i] == 0)
continue;
else
b++;
if (b == m) // 報數達到m的時候置爲0
{
vt[i] = 0;
b = 0;
a--;
}
}
}
for (auto e : vt)
{
if (e != 0)
cout << e << endl;
}
}
system("pause");
return 0;
}