#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 1e5;

struct INT
{
    int a[N];
    INT()
    {
        memset(a,0,sizeof(a));
    }
    void rd()
    {
        char s[N];
        scanf("%s",s);
        a[0] = strlen(s);
        for(int i = 1; i <= a[0]; i++)
            a[i] = s[a[0] - i] - ‘0‘;
        return;
    }
    void print()
    {
        for(int i = a[0]; i >= 1; i--)
            printf("%d",a[i]);
        puts("");
        return;
    }
    INT operator + (const INT &b) const
    {
        INT c;
        c.a[0] = max(a[0],b.a[0]);
        for(int i = 1; i <= c.a[0]; i++)
        {
            c.a[i] += a[i] + b.a[i];
            c.a[i + 1] += c.a[i] / 10;
            c.a[i] %= 10;
        }
        if(c.a[c.a[0] + 1]) c.a[0]++;
        return c;
    }
    bool operator < (const INT &b) const
    {
        if(a[0] != b.a[0]) return a[0] < b.a[0];
        for(int i = a[0]; i >= 1; i--)
            if(a[i] != b.a[i]) return a[i] < b.a[i];
        return false;
    }
    INT operator - (INT b) const
    {
        INT t;
        memcpy(t.a,a,sizeof(a));
        if(t < b)
        {
            printf("-");
            swap(t,b);
        }
        for(int i = 1; i <= t.a[0]; i++)
        {
            if(t.a[i] < b.a[i]) t.a[i] += 10, t.a[i + 1]--;
            t.a[i] -= b.a[i];
        }
        while(t.a[0] > 1 && !t.a[t.a[0]]) t.a[0]--;
        return t;
    }
    INT operator * (const INT &b) const
    {
        INT c;
        for(int i = 1; i <= a[0]; i++)
        {
            int w = 0;
            for(int j = 1; j <= b.a[0]; j++)
            {
                c.a[i + j - 1] += a[i] * b.a[j] + w;
                w = c.a[i + j - 1] / 10;
                c.a[i + j - 1] %= 10;
            }
            c.a[i + b.a[0]] += w;
        }
        c.a[0] = a[0] + b.a[0];
        if(!c.a[c.a[0]]) c.a[0] --;
        return c;
    }
} a,b,c;

int main()
{
    a.rd();
    b.rd();
    // c = a + b;
    // c = a - b;
    // c = a * b;
    c.print();
    return 0;
}

高精度模板