char* kth_word_in_mth_sentence_of_nth_paragraph(char**** document, int k, int m, int n) {
    return document[n-1][m-1][k-1];
}

char** kth_sentence_in_mth_paragraph(char**** document, int k, int m) { 
    return document[m-1][k-1];
}

char*** kth_paragraph(char**** document, int k) {
    return document[k-1];
}

char**** get_document(char* text) {
    int i=0,j=0,k=0,n_para = 0, n_sent[MAX_PARAGRAPHS] = {0}, n_word[MAX_PARAGRAPHS][MAX_CHARACTERS] = {{0}};
    char ****doc = NULL;
    text[strlen(text)] = '\n';
    text[strlen(text)] = '\0';
    //printf("%s\n", text);
    while(text[i] != '\0') {
        if(text[i] == ' ') {
            n_word[n_para][n_sent[n_para]]++;
            i++;
            continue;
        }
        else if(text[i] == '.') {
            n_word[n_para][n_sent[n_para]]++;
            n_sent[n_para]++;
            i++;
            continue;
        }
        else if(text[i] == '\n') {
            n_para++;
            i++;
        } else {
            i++;
        }
    }
    doc = (char ****)calloc(n_para, sizeof(char ***));
    char *str = text;
    char *reserve = NULL;
    for(i = 0; i < n_para; i++) {
        *(doc+i) = (char ***) calloc(n_sent[i], sizeof(char **));
        //printf("n_sent[%d] = %d\n", i, n_sent[i]);
        for(j = 0; j < n_sent[i]; j++) {
            *(*(doc+i)+j) = (char **) calloc(n_word[i][j], sizeof(char *));
            //printf("n_word[%d][%d] = %d\n", i, j, n_word[i][j]);
            for(k = 0; k < n_word[i][j]; k++) {
                *(*(*(doc+i)+j)+k) = (char *)calloc(100, sizeof(char));
                doc[i][j][k] = strtok_r(str, " .\n", &reserve);
                if(i == 0 && j == 0 && k == 0)
                    str = NULL;
            }
        }
    }
    return doc;
}