#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <signal.h>
#include <string.h>
/* int ob (unsigned long long char * matrika, unsigned long long * obiskan, unsigned long long besed, unsigned long long ttl) {
for (int i = 0; i < besed; i++) {
for (int j = 0; j < besed; j++) {
if (matrika[i*d+j] && obiskan[j]) {
if (obiskan[i] == 0) {
obiskan[i] = obiskan[j]+1;
continue;
}
if (obiskan[j]+1 < obiskan[i])
obiskan[i] = obiskan[j]+1; // če obstaja krajša pot
}
}
}
} */
unsigned long long naivno (unsigned char * matrika, unsigned long long * obiskan, unsigned long long besed, unsigned long long ttl, unsigned long long d, unsigned long long lok) {
#ifndef EVAL
fprintf(stderr, "ttl je %llu\n", ttl);
#endif
if (!ttl)
return 0;
// if (obiskan[lok]) // nič več, smo že
// return 0;
obiskan[lok]++;
unsigned long long povezav = 1;
for (unsigned long long i = 0; i < besed; i++) {
if (matrika[besed*i+lok])
povezav += naivno(matrika, obiskan, besed, ttl-1, d, i);
}
return povezav;
}
int main (void) {
char buf[256];
fgets(buf, 256, stdin);
char * c;
unsigned long long s = strtoul(buf, &c, 10);
unsigned long long d = strtoul(++c, &c, 10);
unsigned long long n = strtoul(++c, &c, 10); // število otrok
unsigned long long z = strtoul(++c, &c, 10); // ??? . edit kasneje: aja, razumem, prva izrečena beseda
char ** w = malloc(sizeof(char *)*s);
unsigned long long i = 0;
while (i++ <= s) {
fgets(buf, 256 /* še newline in NULL */, stdin);
w[i-1] = strdup(buf);
#ifndef EVAL
fprintf(stderr, "w[%llu]: %s\n", i-1, w[i-1]);
#endif
if (ferror(stdin) || feof(stdin))
break;
}
unsigned char matrika[s*s]; // en megabajt največ, gucci
memset(matrika, '\0', s*s);
for (unsigned long long i = 0; i < s; i++) {
#ifndef EVAL
fprintf(stderr, "%llu\n", i);
#endif
for (unsigned long long j = 0; j < s; j++) {
int ne = 0;
for (unsigned long long k = 0; k < d; k++)
if (w[i][k] != w[j][k])
ne++;
if (ne <= 1)
matrika[s*i+j] = 1;
}
}
#ifndef EVAL
for (unsigned long long i = 0; i < s; i++) {
for (unsigned long long j = 0; j < s; j++) {
fprintf(stderr, "%u ", matrika[s*i+j]);
}
fprintf(stderr, "\n");
}
#endif
unsigned long long obiskan[s]; // da vpisujemo TTLje
memset(obiskan, '\0', s*sizeof(unsigned long long));
fprintf(stderr, "%llu\n", naivno(matrika, obiskan, s, n+1, d, z));
unsigned cx = 0;
for (int i = 0; i < s; i++) {
if (obiskan[i])
cx++;
}
fprintf(stdout, "%u\n", cx);
/*
int ret = ob(matrika, obiskan, d, n);
if (ret == -1) { // nihče ni bil dodatno obiskan
unsigned long long obiskanih = 0;
for (int i = 0; i < d; i++)
if (obiskan[d])
obiskanih++;
fprintf(stdout, "%u\n", obiskanih);
return 0;
}*/
return 0;
}