The problem gives a c source full of macros and ascii art.

First get the preprocessing result using 'gcc -E' or 'gcc --save-temps', then format it using tools like indent.
ignore the huge array, you will get some basic functions.

```
/* simple linked list */
struct s {
struct s*s;
};
/* list insert head */
static struct s *z ( struct s*n) {
struct s*t=n ;
n =malloc (sizeof(struct s)) ;
n-> s= t;
return n ;
}
/* list length */
static int pi (struct s *n ) {
int x =0;
for(; n ; n=n-> s,x++) ;
return x;;
}
/* create list of size n */
static struct s*ip(int n) {
struct s*s=0;
for(int i=0; i<n; i++) {
s=z(s);
}
return s;
}
/* compare length of two lists, return 0 if equal */
static int pc(struct s*n,struct s*o) {
for(; n&&o; n=n->s,o=o->s);
return n||o;
}
/* simple per-byte transform, only 896/1024 bytes are transformed */
static void df(int*p) {
register n=128;
switch(1024%8) {
case 0:
do {
*p^=0x63 ; p++;
case 7:
*p^=48; p++;
case 6:
case 5:
*p<<=4; p++;
case 4:
*p<<=2; p++;
case 3:
*p*=55; p++;
case 2:
*p-=-97; p++;
case 1:
*p+=44; p++ ;
}
while(--n>0);
}
}
/* simple copy */
static void dc(int*d,char*s) {
register int n=(1024+7)/8;
switch (1024%8) {
case 0:
do {
*d++=*s++;
case 7: *d++=*s++;
case 6: *d++=*s++;
case 5: *d++=*s++;
case 4: *d++=*s++;
case 3: *d++=*s++;
case 2: *d++=*s++;
case 1: *d++=*s++;
}
while(--n>0);
}
}
/* checker */
static int ch (int*n) {
struct s*a[1024]= {...};
struct s*p;
for(int i=0; i<1024; i++) {
p=ip(i[n]); /* create list of given length */
if(pc(p,i[a])) { /* compare list length with given one */
return 0;
}
}
return 1;
}
int main(void) {
static char b[1024];
static int i[1024];
fgets(b,1024, stdin);
dc(i,b); /* copy */
df(i); /* transform */
return !!!!!!!!!!!!!!!!!!!!!!!ch(i); /* compare */
}
```

The rest is simple:
1. calculate the length of each list in a;
2. perform reverse transform of df.
```
# counting list lengths (s is the string representation of the array a in function ch().
v = [x.count('z') for x in s.split(',')]
# reverse transform of df
o, i = '', 0
for x in v[:-128]:
if i == 0:
o += chr(x^0x63)
elif i == 1:
o += chr(x^48)
elif i == 2:
o += chr(x>>4)
elif i == 3:
o += chr(x>>2)
elif i == 4:
o += chr(x/55)
elif i == 5:
o += chr(x-97)
print o
```