#include<bits/stdc++.h>
using namespace std;

vector<int> a , b ;

vector<int> add(const vector<int> &a, const vector<int> &b)
{
    //默认是a长 b短
    if(b.size() > a.size()) return add(b,a) ;
    int t = 0;
    vector<int> c ;
    for(int i=0; i<a.size() || t; i++){
        if(i<a.size()) t += a[i];
        if(i<b.size()) t += b[i];
        c.emplace_back(t%10);
        t /= 10;
    } 

    reverse(c.begin() , c.end() ) ;
    return c;
}


vector<int> jian(const vector<int> &a, const vector<int> &b) 
{
    vector<int> c ;
    int t = 0;//借位 
    for(int i=0; i<a.size(); i++){
        t = a[i] - t;
        if(i < b.size()) t -= b[i];

        c.push_back( (t+10) % 10) ;
        if(t < 0 ) t = 1;
        else t = 0; 
    }

    //去除前导0
    while(c.back() == 0 && c.size() > 1) c.pop_back() ; 

    reverse(c.begin(), c.end() ) ;
    return c ;

}

//字符串比较 
bool cmp(string s1, string s2){

    if(s1.size()!= s2.size()){
        for(int i=0; i<max(s1.size() , s2.size()); i++){
            if(s2[i] != s1[i]) return s1[i] < s2[i];
        }
    }else{
        return s1 < s2 ; 
    }

}


vector<int> mul(const vector<int> &a, int b)
{
    vector<int> c;
    int t = 0;
    for(int i=0; i<a.size() || t; i++){
        if(i < a.size()) t += b * a[i];
        c.push_back(t % 10);
        t/=10;
    }

    while(c.back() == 0 && c.size() > 1) c.pop_back() ; 

    reverse(c.begin(), c.end() ) ;
    return c ;



} 


int main(){
    // "987"
    // "43"
    string s1;
    string s2;
    int b;
    cin >> s1 >> b;

    for(auto i :s1) a.emplace_back(i-'0');reverse(a.begin(), a.end());
    //for(auto i :s2) b.emplace_back(i-'0');reverse(b.begin(), b.end());
    //高精度加法 
    //vector<int> c = add(a,b);
    //高精度减法 
//  vector<int> c;
//  if(cmp(s1,s2)) {
//      cout << '-';
//      c = jian(b,a);
//  }else{
//      c = jian(a,b);
//  }

    //高精度乘以低精度 string s1; int b;
    vector<int> c = mul(a, b); 
    for(auto i : c) {
        cout << i  ;
    }



    return 0;
}

—— 本文来自火龙信奥（义乌睿码科技）：义乌青少年信息学奥赛与编程教育平台，专注 CSP-J/S、NOIP、GESP 竞赛培训，线上线下融合教学，助力编程升学。网址：hlcoding.com