#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char* crypt (char* word)
{
    char values[] = "abcdefghijklmnopqrstuvwxyz";
    static char String[5];
    int i;
    int key = 3;

    for (i = 0; i < strlen(word); i++)
    {
        char find = word[i];
        const char *ptr = strchr(values, find);
        int index = ptr - values;
        String[i] = values[index+key];

    }

    return String;
}

int main(int argc, char *argv[])
{
    char word[5]="abcd";
    char* result=crypt(word);
    printf("%s\n", result);

    return 0;
}