#include<iostream>
#include<fstream>
#include<stdlib.h>
using namespace std;
struct book
{char name[20];
char no[10];
int num;
float price;
};
void main()
{
    fstream iolib("data.txt",ios::out|ios::in,ios::binary);
    if(!iolib)
    {cout<<"flie can't open"<<endl;
    exit(1);}
    book temp;
    for(int i=0;i<20;i++)
    {cin>>temp.name >>temp.no>>temp.num>>temp.price;
    iolib.write((char*)&temp,sizeof(book));}
    for(int i=20;i>10;i--)
    {
        iolib.seekg((i-1)*sizeof(book),ios::beg);
        iolib.read((char*)&temp,sizeof(book));
        iolib.write((char*)&temp,sizeof(book));
    }
    cin>>temp.name >>temp.no>>temp.num>>temp.price;
    iolib.seekg(10*sizeof(book),ios::beg);
    iolib.write((char*)&temp,sizeof(book));
    int total=0;
    float sum=0.0;
    iolib.seekg(0,ios::beg);
    {cout<<"name"<<'\t'<<"no"<<'\t'<<"num"<<'\t'<<"price"<<endl;}
    for(int i=0;i<20;i++)
    {iolib.read((char*)&temp,sizeof(book));
    cout<<temp.name<<temp.no<<temp.num<<temp.price<<endl;
    total+=temp.num;
    sum+=temp.num*temp.price;
    }
    cout<<"total number:"<<total<<'\t'<<"amount"<<sum;
}