Maybe I dont know what they want but program count letters corectly.
package pl.codegym.task.task18.task1816;
/*
ABC
*/
import java.io.BufferedReader;
import java.io.FileReader;
public class Solution {
public static void main(String[] args) throws Exception {
String string = "";
for (int i = 0; i < args.length; i++) {
FileReader fileReader = new FileReader(args[i]);
BufferedReader bufferedReader = new BufferedReader(fileReader);
string += bufferedReader.readLine();
fileReader.close();
bufferedReader.close();
}
int sum = 0;
String repalcedString = string.replaceAll("[a-zA-Z]", "a");
for (int i = 0; i < repalcedString.length(); i++) {
if (repalcedString.charAt(i) == 97){
sum++;
}
}
System.out.println(sum);
}
}