#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

int dig[],sz;

void dec(ll k)

{

    sz = ;

    while(k){

        dig[sz++] = k%;

        k /= ;

    }

    reverse(dig,dig+sz);

}

int main()

{

    freopen("amusing.in","r",stdin);

    freopen("amusing.out","w",stdout);

    ll K,M; cin>>K>>M;

    ll a = ;

    dec(K);

    for(int i = sz; i > ; i--){

        ll data = ,low = ;

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

            data =  data*+dig[j];

            low *= ;

        }

        a += data - low/+;

    }

    if(a > M) {

        printf("0\n");

        return ;

    }

    if(a == M){

        printf("%I64d\n",K);

        return ;

    }

    ll b = M-a;

    for(int i = sz+; ; i++){

        ll data = ,low = ;

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

            data = data*+dig[j];

            low *= ;

        }

        ll t = data - low/;

        if(!t) { printf("0\n"); return ; }

        if(b <= t){

            low /= ;

            printf("%I64d\n",b-+low);

            return ;

        }

        b -= t;

    }

    return ;

}