#include<iostream>

#include<string>

#define LEN 100

using namespace std;

void add(char a[],char b[]){

	/*********************装换*********************/

	int num1[LEN];

	int num2[LEN];

	for (int i = 0; i < LEN; i++){

		num1[i] = 0;

		num2[i] = 0;

	}

	int lena = strlen(a);

	int lenb = strlen(b);
	for (int i = lena - 1,j = 0; i >= 0; i--){

		num1[j++] = a[i] - '0';

	}
	for (int i = lenb - 1,j = 0; i >= 0; i--){

		num2[j++] = b[i] - '0';

	}

	for (int i = 0; i < LEN; i++){

		num1[i] += num2[i];

	}

	/*****************求和*******************/

	for (int i = 0; i < LEN; i++)

	{

		if (num1[i] >= 10){

			num1[i + 1] += num1[i] / 10;

			num1[i] %= 10;

		}

	}

/************打印************************/

	int i;

	for (i = LEN - 1; i > 0; i--){

		if (num1[i] != 0)

			break;

	}

	for (; i >= 0; i--)

		cout << num1[i];

	cout << endl;

}
void mul(char a[],char b[])

{

/****************装换****************/

	int num1[LEN];

	int num2[LEN];

	for (int i = 0; i < LEN; i++){

		num1[i] = 0;

		num2[i] = 0;

	}

	int lena = strlen(a);

	int lenb = strlen(b);
	for (int i = lena - 1,j = 0; i >= 0; i--){

		num2[j++] = b[i] - '0';

	}

/************************乘积*************/

	int sum[LEN];

	for (int i = 0; i < LEN; i++){

		sum[i] = 0;

	}
	for (int i = 0; i < lena; i++)

		for (int j = 0; j < lenb; j++){

			sum[i + j] += num1[i] * num2[j];

			if (sum[i + j] >= 10){

				sum[i + j + 1] += sum[i + j] / 10;

				sum[i + j] %= 10;

			}

		}

	/*******************打印*******************/

	int i;

	for (i = LEN - 1; i > 0; i--){

		if (sum[i] != 0)

			break;

	}

	for (; i >= 0; i--)

		cout << sum[i];

	cout << endl;

}
void mod(char a[],int mod){

	///****************装换****************/

	//int num1[LEN];

	//int num2[LEN];

	//for (int i = 0; i < LEN; i++){

	//	num1[i] = 0;

	//	num2[i] = 0;

	/