#include<fstream.h>
int main()
{ unsigned long i,j,n,a,b,d,nr=0,x;
ifstream f("pascal.in");
f>>n>>d;
f.close();
if(d==1)
{ofstream g("pascal.out"); g<<n+1;g.close();}
else
{a=1;
if(a%d==0)
nr=2;
if(n%2==0)
{x=1;nr=nr-1;}
else
x=0;
for(i=1;i<=(n+1)/2+x;i++)
{b=a*(n-i+1)/i;
if(b%d==0){nr=n-i;  break;}
a=b;}
ofstream g("pascal.out");
g<<nr;
g.close();
}
return 0;}