Вот сама ошибка - при вводе любого символа, в данном случае 2;
Exception in thread "main" java.io.FileNotFoundException: 2 (Не удается найти указанный файл)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)
at com.javarush.task.task18.task1802.Solution.main(Solution.java:16)
Сам код решения =>
package com.javarush.task.task18.task1802;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
/*
Минимальный байт
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String str = reader.readLine();
int min = 255;
try(FileInputStream stream = new FileInputStream(str)){
while (stream.available() > 0){
int buff = stream.read();
if (min > buff) {
min = buff;
}
}
}
System.out.println(min);
}
}