#include<bits/stdc++.h>

#define ri register signed

#define p(i) ++i

namespace IO{

    char buf[1<<21],*p1=buf,*p2=buf;

    #define gc() p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?(-1):*p1++

    struct nanfeng_stream{

        template<typename T>inline nanfeng_stream &operator>>(T &x) {

            ri f=0;x=0;register char ch=gc();

            while(!isdigit(ch)) {f|=ch=='-';ch=gc();}

            while(isdigit(ch)) {x=(x<<1)+(x<<3)+(ch^48);ch=gc();}

            return x=f?-x:x,*this;

        }

    }cin;

}

using IO::cin;

namespace nanfeng{

    #define FI FILE *IN

    #define FO FILE *OUT

    template<typename T>inline T cmax(T x,T y) {return x>y?x:y;}

    template<typename T>inline T cmin(T x,T y) {return x>y?y:x;}

    static const int N=7e7;

    int prime[]={0,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47};

    int mx[N+1],prim[N],nm,B,k,cnt;

    bool vis[N+1];

    inline void Getprime() {

        for (ri i(2);i<=N;p(i)) {

            if (!vis[i]) mx[prim[p(nm)]=i]=i;

            for (ri j(1);j<=nm&&prim[j]*i<=N;p(j)) {

                ri l=prim[j];

                vis[l*i]=1,mx[l*i]=mx[i];

                if (!(i%l)) break;

            }

        }

    }

    inline int main() {

        //FI=freopen("nanfeng.in","r",stdin);

        //FO=freopen("nanfeng.out","w",stdout);

        cin >> B >> k;

        Getprime();

        const int PB=prime[B];

        for (ri i(1);i<=N;p(i)) {

            if (mx[i]>PB) continue;

            p(cnt);

            if (cnt==k) {printf("%d\n",i);break;}

        }

        return 0;

    }

}

int main() {return nanfeng::main();}