class chiper():
    def __init__(self):
        self.d = 0x87654321
        k0 = 0x67452301
        k1 = 0xefcdab89
        k2 = 0x98badcfe
        k3 = 0x10325476
        self.k = [k0, k1, k2, k3]

    def e(self, n, v):
        from ctypes import c_uint32

        def MX(z, y, total, key, p, e):
            temp1 = (z.value >> 6 ^ y.value << 4) + \
                (y.value >> 2 ^ z.value << 5)
            temp2 = (total.value ^ y.value) + \
                (key[(p & 3) ^ e.value] ^ z.value)
            return c_uint32(temp1 ^ temp2)
        key = self.k
        delta = self.d
        rounds = 6 + 52//n
        total = c_uint32(0)
        z = c_uint32(v[n-1])
        e = c_uint32(0)

        while rounds > 0:
            total.value += delta
            e.value = (total.value >> 2) & 3
            for p in range(n-1):
                y = c_uint32(v[p+1])
                v[p] = c_uint32(v[p] + MX(z, y, total, key, p, e).value).value
                z.value = v[p]
            y = c_uint32(v[0])
            v[n-1] = c_uint32(v[n-1] + MX(z, y, total,
                              key, n-1, e).value).value
            z.value = v[n-1]
            rounds -= 1
        return v

    def bytes2ints(self,cs:bytes)->list:
        new_length=len(cs)+(8-len(cs)%8)%8
        barray=cs.ljust(new_length,b'\x00')
        i=0
        v=[]
        while i < new_length:
            v0 = int.from_bytes(barray[i:i+4], 'little')
            v1 = int.from_bytes(barray[i+4:i+8], 'little')
            v.append(v0)
            v.append(v1)
            i += 8
        return v

def check(instr:str,checklist:list)->int:
    length=len(instr)
    if length%8:
        print("Incorrect format.")
        exit(1)
    c=chiper()
    v = c.bytes2ints(instr.encode())
    output=list(c.e(len(v),v))
    i=0
    while(i<len(checklist)):
        if i<len(output) and output[i]==checklist[i]:
            i+=1
        else:
            break
    if i==len(checklist):
        return 1
    return 0    

if __name__=="__main__":
    ans=[1374278842, 2136006540, 4191056815, 3248881376]
    # generateRes()
    flag=input('Please input flag:')
    res=check(flag,ans)
    if res:
        print("Congratulations, you've got the flag!")
        print("Flag is *ctf{your_input}!")
        exit(0)
    else:
        print('Nope,try again!')

#include <stdio.h>  
#include <stdint.h>  
#include<windows.h>
#define DELTA 0x87654321
#define MX (((z>>6^y<<4) + (y>>2^z<<5)) ^ ((sum^y) + (key[(p&3)^e] ^ z)))  

void btea(uint32_t *v, int n, uint32_t const key[4])
{
  uint32_t y, z, sum;
  unsigned p, rounds, e;
  if (n < -1)      /* Decoding Part */
  {
    n = -n;
    rounds = 6 + 52 / n;
    sum = rounds*DELTA;
    y = v[0];
    do
    {
      e = (sum >> 2) & 3;
      for (p = n - 1; p>0; p--)
      {
        z = v[p - 1];
        y = v[p] -= MX;
      }
      z = v[n - 1];
      y = v[0] -= MX;
      sum -= DELTA;
    } while (--rounds);
  }
}
int main()
{
      uint32_t v[4] = {1374278842, 2136006540, 4191056815, 3248881376};
      uint32_t const k[4] = { (unsigned int)0x67452301, (unsigned int)0xefcdab89, (unsigned int)0x98badcfe, (unsigned int)0x10325476};
      int n = 4; 
      // n的绝对值表示v的长度，取正表示加密，取负表示解密  
      // v为要加密的数据是两个32位无符号整数  
      // k为加密解密密钥，为4个32位无符号整数，即密钥长度为128位  
      btea(v, -n, k);
      printf("%x %x %x %x \n", v[0], v[1],v[2],v[3]);
      for (int i = 0; i < 16; i++)
    {
        printf("%c", *((char *)v + i));
    }
}//通用xxtea模板
//脚本来源https://blog.csdn.net/m0_51713041/article/details/115535776
//yOUar3g0oD@tPw5H