# 题目

12345678900
98765432100

## Sample Output

1219326311126352690000

>高精度算法<

# 代码

```/*
By:OhYee
Github:OhYee
Blog:http://www.oyohyee.com/
Email:oyohyee@oyohyee.com

かしこいかわいい？
エリーチカ！

*/
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <string>
#include <iostream>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <functional>
using namespace std;

#define REP(n) for(int o=0;o<n;o++)
#define Max(a,b) (a>b?a:b)
#define Min(a,b) (a<b?a:b)
const int maxn = 10000;

class bigNumber {
private:
int num[maxn + 1];
public:
bigNumber() {
init();
}
void init() {
memset(num,0,sizeof(num));
}
bigNumber operator = (const char *str) {
init();
num[0] = strlen(str);
REP(num[0])num[num[0] - o] = str[o] - '0';
return *this;
}
bigNumber operator = (const bigNumber& rhs) {
init();
REP(rhs.num[0] + 1)num[o] = rhs.num[o];
return *this;
}
bigNumber operator = (long long rhs) {
init();
int i = 1;
while(rhs) {
num[i] = rhs % 10;
rhs /= 10;
i++;
}
num[0] = i - 1;
return *this;
}
bool operator < (const bigNumber rhs)const {
if(num[0] != rhs.num[0])return (num[0] < rhs.num[0]);
REP(num[0]) {
int temp = num[0] - o;
if(num[temp] != rhs.num[temp])return (num[temp] < rhs.num[temp]);
}
return 0;
}
bool operator > (const bigNumber rhs)const {
if(num[0] != rhs.num[0])return (num[0] > rhs.num[0]);
REP(num[0]) {
int temp = num[0] - o;
if(num[temp] != rhs.num[temp])return (num[temp] > rhs.num[temp]);
}
return 0;
}
bool operator == (const bigNumber rhs)const {
return !(*this > rhs || *this < rhs);
}
bool operator <= (const bigNumber rhs)const {
return *this < rhs || *this == rhs;
}
bigNumber operator + (const bigNumber rhs)const {
bigNumber temp;
int len;
len = num[0] > rhs.num[0] ? num[0] : rhs.num[0];
len++;
REP(len) {
temp.num[o + 1] += num[o + 1] + rhs.num[o + 1];
temp.num[o + 2] += temp.num[o + 1] / 10;
temp.num[o + 1] %= 10;
}
REP(len) {
if(temp.num[len - o] != 0) {
temp.num[0] = len - o;
break;
}
}
return temp;
}
bigNumber operator + (const long long rhs)const {
bigNumber temp1,temp2;
temp1 = *this;
temp2 = rhs;
return temp1 + temp2;
}
bigNumber operator * (const bigNumber rhs)const {
bigNumber temp;
int len;
len = num[0] + rhs.num[0];
//len++;
for(int i = 1;i <= num[0];i++) {
for(int j = 1;j <= rhs.num[0];j++) {
temp.num[i + j - 1] += num[i] * rhs.num[j];
temp.num[i + j] += temp.num[i + j - 1] / 10;
temp.num[i + j - 1] %= 10;
}
}
REP(len) {
if(temp.num[len - o] != 0) {
temp.num[0] = len - o;
break;
}
}
return temp;
}
bigNumber operator * (const long long rhs)const {
bigNumber temp1,temp2;
temp1 = *this;
temp2 = rhs;
return temp1 * temp2;
}
bigNumber operator - (const bigNumber rhs)const {
bigNumber temp,a,b;
temp = Max(*this,rhs);
b = Min(*this,rhs);
a = temp;
temp.init();
int len = a.num[0];
REP(len) {
temp.num[o + 1] += 10 + a.num[o + 1] - b.num[o + 1];
temp.num[o + 2]--;
temp.num[o + 2] += temp.num[o + 1] / 10;
temp.num[o + 1] %= 10;
}
REP(len) {
if(temp.num[len - o] != 0) {
temp.num[0] = len - o;
break;
}
}
return temp;
}
bigNumber operator - (const long long rhs)const {
bigNumber temp1,temp2;
temp1 = *this;
temp2 = rhs;
return temp1 - temp2;
}
bigNumber operator / (const bigNumber rhs)const {
bigNumber a;
int it = num[0];

bigNumber d;
bigNumber c;

while(it > 0) {
a = (d * 10) + num[it];
c = c * 10;

int t;
REP(9) {
if(a < rhs * (o + 1)) {
t = o;
break;
}
t = 9;
}
c = c + t;
d = a - rhs*t;
it--;
}
return c;
}
bigNumber operator / (const long long rhs)const {
bigNumber temp1,temp2;
temp1 = *this;
temp2 = rhs;
return temp1 / temp2;
}
bigNumber operator % (const bigNumber rhs)const {
bigNumber a;
int it = num[0];

bigNumber d;
bigNumber c;

while(it > 0) {

a = (d * 10) + num[it];
c = c * 10;

int t;
REP(9) {
if(a < rhs * (o + 1)) {
t = o;
break;
}
t = 9;
}
c = c + t;
d = a - rhs*t;
it--;
}
return d;
}
bigNumber operator % (const long long rhs)const {
bigNumber temp1,temp2;
temp1 = *this;
temp2 = rhs;
return temp1 % temp2;
}
void p() {
if(num[0] == 0)
printf("0");
REP(num[0]) {
printf("%d",num[num[0] - o]);
}
}
};

bigNumber a,b,c;
char aa[maxn],bb[maxn];
bool Do() {

if(scanf("\n%s\n%s",aa,bb)==EOF)
return false;

a = aa;
b = bb;
c = a * b;
c.p();

putchar('\n');
return true;
}

int main() {
while(Do());
return 0;
}
```