Language: Java

import java.io.*;
import java.util.*;

public class fastIO {
    public static void main(String[] args) {
        InputReader in = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        for (int i = 1; i <= 5; ++i) {
            int temp = in.nextInt();
            if (temp == 0)
                w.println(i);
        }
        w.close();
    }
}

class InputReader {

    private final InputStream stream;
    private final byte[] buf = new byte[8192];
    private int curChar, snumChars;
    private SpaceCharFilter filter;

    public InputReader(InputStream stream) {
        this.stream = stream;
    }

    public int snext() {
        if (snumChars == -1)
            throw new InputMismatchException();
        if (curChar >= snumChars) {
            curChar = 0;
            try {
                snumChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (snumChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public int nextInt() {
        int c = snext();
        while (isSpaceChar(c)) {
            c = snext();
        }
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = snext();
        }
        int res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = snext();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public long nextLong() {
        int c = snext();
        while (isSpaceChar(c)) {
            c = snext();
        }
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = snext();
        }
        long res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = snext();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public int[] nextIntArray(int n) {
        int a[] = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = this.nextInt();
        }
        return a;
    }

    public long[] nextLongArray(int n) {
        long a[] = new long[n];
        for (int i = 0; i < n; i++) {
            a[i] = this.nextLong();
        }
        return a;
    }

    public String readString() {
        int c = snext();
        while (isSpaceChar(c)) {
            c = snext();
        }
        StringBuilder res = new StringBuilder();
        do {
            res.appendCodePoint(c);
            c = snext();
        } while (!isSpaceChar(c));
        return res.toString();
    }

    public String nextLine() {
        int c = snext();
        while (isSpaceChar(c))
            c = snext();
        StringBuilder res = new StringBuilder();
        do {
            res.appendCodePoint(c);
            c = snext();
        } while (!isEndOfLine(c));
        return res.toString();
    }

    public boolean isSpaceChar(int c) {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    private boolean isEndOfLine(int c) {
        return c == '\n' || c == '\r' || c == -1;
    }

    public interface SpaceCharFilter {
        public boolean isSpaceChar(int ch);
    }
}

Compiler output:
Main.java:4: error: class fastIO is public, should be declared in a file named fastIO.java
public class fastIO {
       ^
1 error