#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

int p,x,y,ai[],ans;

bool check(int xx)

{

    if(xx<y) return false;

    int i=(xx/)%;

    for(int j=;j<=;j++)

    {

        i=(i*+)%;

        if(p==+i) return true;

    }

    return false;

}

int main()

{

    scanf("%d%d%d",&p,&x,&y);

    int pos=x;

    while(pos>=y)

    {

        if(check(pos))

        {

            printf("");

            return ;

        }

        pos-=;

    }

    while(x<y) x+=,ans++;

    while()

    {

        if(check(x)||check(x-))

        {

            printf("%d",ans);

            return ;

        }

        x+=,ans++;

    }

    return ;

}