#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_LINE_LENGTH 1000

int main() {
    char input_file_path[] = "data.txt";
    char output_file_path[] = "result.txt";

    FILE *input_file = fopen(input_file_path, "r");
    FILE *output_file = fopen(output_file_path, "w");

    if (input_file == NULL || output_file == NULL) {
        perror("Error opening files");
        return 1;
    }

    char line[MAX_LINE_LENGTH];

    while (fgets(line, sizeof(line), input_file) != NULL) {
        char *token = strtok(line, " \t\n");
        while (token != NULL) {
            if (token[0] == 'a' || token[0] == 'A') {
                fprintf(output_file, "%s ", token);
            }
            token = strtok(NULL, " \t\n");
        }
        fprintf(output_file, "\n");
    }

    fclose(input_file);
    fclose(output_file);

    return 0;
}