/*
TASK:crazy
LANG:C
*/
#include <stdio.h>
#include "module.h"
#include <math.h>

#define MAXN 512

int p0(int a)
{   int i;
    for (i=2;i<a;i++)
    {   if ((a%i)==0) return i;
    }
    return 0;
}

int p1(int a)
{   int i;
    for (i=3;i<a;i++)
    {   if ((a%i)==0) return i;
    }
    return 0;
}


int ch2(int a)
{   for (;a!=1;)
    {   if (a%2) return 0;
        a=a/2;
    }
    return 1;
}


int main()
{   long a[2],b;
    for (;;)
    {   getnum(&a[0],&a[1]);
        // b=0;
        b=0;
        
        if (a[b]==3)
        {  a[b]=a[b]+1;
           a[!b]=p1(a[!b]);goto setit;
        }
        /*else if ( (a[b]==4) || (a[b]==2))
        {    a[b]=a[b]+1;
             a[!b]=p0(a[!b]);goto setit;
        } */
        else if ( (p0(a[b])) && (!p0(a[!b]+1)) )
        {    a[b]=p0(a[b]);
             a[!b]++;goto setit;
        }
        else if ( (a[b]%3==0) && (ch2(a[!b]+1)) && (a[b]!=3) )
        {    a[b]=3;
             a[!b]++;goto setit;
        }
        else if ( (a[b]%5==0) && (ch2(a[!b]+1)) && (a[b]!=5) )
        {    a[b]=5;
             a[!b]++;goto setit;
        }

        


        // b=1;
        b=1;

        if (a[b]==3)
        {  a[b]=a[b]+1;
           a[!b]=p1(a[!b]);goto setit;
        }
        /*else if ( (a[b]==4) || (a[b]==2))
        {    a[b]=a[b]+1;
             a[!b]=p0(a[!b]);goto setit;
        }*/
        else if ( (p0(a[b])) && (!p0(a[!b]+1)) )
        {    a[b]=p0(a[b]);
             a[!b]++;goto setit;
        }
        else if ( (a[b]%3==0) && (ch2(a[!b]+1)) && (a[b]!=3) )
        {    a[b]=3;
             a[!b]++;goto setit;
        }
        else if ( (a[b]%5==0) && (ch2(a[!b]+1)) && (a[b]!=5) )
        {    a[b]=5;
             a[!b]++;goto setit;
        }


        // unsure b=0;



        b=0;
        if ( (a[b]==7) && (ch2(a[!b])) )
        {  a[b]=8;
           a[!b]=8;goto setit;
        }
        
        b=1;
        if ( (a[b]==7) && (ch2(a[!b])) )
        {  a[b]=8;
           a[!b]=8;goto setit;
        }
                
        
        setit:
              setnum(a[0],a[1]);
    }
 
    return 0;
}
