#include<bits/stdc++.h> //接下来奉上全网最全c++代码
#include<assert.h>
#include<ctype.h>
#include<errno.h>
#include<ege.h>
#include<emmintrin.h>
#include<errors.h>
#include<errorrep.h>
#include<evcode.h>
#include<exception>
#include<excpt.h>
#include<exdisp.h>
#include<exdispid.h>
#include<execution>
#include<float.h>
#include<math.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<time.h>
#include<wchar.h>
#include<wchar.h>
#include<wctype.h>
#include<algorithm>
#include<bitset>
#include<cctype>
#include<cerrno>
#include<clocale>
#include<cmath>
#include<complex>
#include<cstdio>
#include<cstring>
#include<ctime>
#include<deque>
#include<execution>
#include<list>
#include<map>
#include<iomanip>
#include<ios>
#include<fenv.h>
#include<iosfwd>
#include<iostream>
#include<ostream>
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<vector>
#include<cwchar>
#include<tgmath.h>
#include<utility>
#include<utime.h>
#include<commdlg.h>
#include<cassert>
#include<complex.h>

using namespace std ;

const long long max_length = 1e9 ; // 可根据实际需求调整最大长度(字符串)

double fast_double_read() //double类型下的快读代码
{
	double x = 0.0 ;
	int sign = 1 ;
	char ch = getchar() ;
	while( ch < '0' || ch > '9' )
		{
			if( ch == '-' )
				sign = - 1 ;
			ch = getchar() ;
		}
	while( ch >= '0' && ch <= '9' )
		{
			x = x * 10 + ch - '0' ;
			ch = getchar() ;
		}
	if( ch == '.' )
		{
			double frac_tion = 0.1 ;
			ch = getchar() ;
			while( ch >= '0' && ch <= '9' )
				{
					x += ( ch - '0' ) * frac_tion ;
					frac_tion /= 10 ;
					ch = getchar() ;
				}
		}
	return x * sign ;
}

char fast_char_read() //char类型下的快读代码
{
	char ch = getchar() ;
	while( ch == '\n' || ch == '\r' || ch == ' ' || ch == '\t' )
		ch = getchar() ;
	return ch ;
}

int fast_int_read() //int类型下的快读代码
{
	int x = 0 ;
	int f = 1 ;
	char ch = getchar() ;
	while( ch < '0' || ch > '9' )
		{
			if( ch == '-' )
				f = -1 ;
			ch = getchar() ;
		}
	while( ch >= '0' && ch <= '9' )
		{
			x = x * 10 + ch - '0' ;
			ch = getchar() ;
		}
	return x * f ;
}

void fast_string_read( char *s ) //string类型下的快读代码
{
	char ch = getchar() ;
	int index = 0 ;
	while( ch == '\n' || ch == '\r' || ch == ' ' || ch == '\t' )
		ch = getchar() ;
	while( ch != '\n' && ch != '\r' && index < max_length - 1 )
		{
			s[index++] = ch ;
			ch = getchar() ;
		}
	s[index] = '\0' ;
} 

char s[max_length] ;

char a , b , c , d ;

int main()
{
	ios::sync_with_stdio( false ) ;
	cin.tie( 0 ) ;
	cout.tie( 0 ) ;
	
	a = fast_double_read() ;
	b = fast_double_read() ;
	c = fast_double_read() ;
	d = fast_double_read() ;
	
	cin >> a >> b >> c >> d ;
	cout << d << "." << c << b << a << "\n" ;
	return 0 ;
}

请问为啥输出不了啊，代码没问题