#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=n+1;   
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;}