Problem:
Score : 100 points

Problem Statement

We have five variables x_1, x_2, x_3, x_4, and x_5.

The variable x_i was initially assigned a value of i.

Snuke chose one of these variables and assigned it 0.

You are given the values of the five variables after this assignment.

Find out which variable Snuke assigned 0.

Constraints

The values of x_1, x_2, x_3, x_4, and x_5 given as input are a possible outcome of the assignment by Snuke.

Input

Input is given from Standard Input in the following format:

x_1 x_2 x_3 x_4 x_5

Output

If the variable Snuke assigned 0 was x_i, print the integer i.

Sample Input 1

0 2 3 4 5

Sample Output 1

1

In this case, Snuke assigned 0 to x_1, so we should print 1.

Sample Input 2

1 2 0 4 5

Sample Output 2

3

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.io.*;
import java.lang.reflect.Array;
import java.math.*;
import java.util.*;

public class Main {
	static final int INF = (int) (1e9 + 10);
	static final long MOD = (int) (1e9 + 7);
	static final int N = (int) (4e5 + 5);
	// static ArrayList<Integer>[] graph;
	// static boolean visited[];
	// static long size[];

	public static void main(String[] args) throws NumberFormatException, IOException {
		FastReader sc = new FastReader();
		PrintWriter pr = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		// Scanner scn = new Scanner(System.in);
		//
		int x1=sc.nextInt();
		int x2=sc.nextInt();
		int x3=sc.nextInt();
		int x4=sc.nextInt();
		int x5=sc.nextInt();
		if(x1==0)
			pr.println("1");
		if(x2==0)
			pr.println("2");
		if(x3==0)
			pr.println("3");
		if(x4==0)
			pr.println("4");
		if(x5==0)
			pr.println("5");
		//
		// Coded to Perfection by Rohan Mukhija
		pr.flush();
		pr.close();
	}

	/*
	 * Template From Here
	 */
	private static boolean possible(long[] arr, long mid, long k,long t) {
		long c = 1;
		long tot=0;
		for (int i = 0; i < arr.length; i++) {
			tot+=(arr[i]);
			if(tot>mid)
			{
				tot=arr[i];
				c++;
			}
		}
		// System.out.println(mid+" "+c);
		if (c <= k)
			return true;
		return false;
	}
	public static class Pair implements Comparable<Pair> {
		int u;
		int v;

		Pair(int u, int v) {
			this.u = u;
			this.v = v;

		}

		public int compareTo(Pair compareEdge) {
			return Long.compare(this.v, compareEdge.v);
		}
	};

	static void sort(long[] a) {
		ArrayList<Long> l = new ArrayList<>();
		for (long i : a)
			l.add(i);
		Collections.sort(l);
		for (int i = 0; i < a.length; i++)
			a[i] = l.get(i);
	}

	static void sort(int[] a) {
		ArrayList<Integer> l = new ArrayList<>();
		for (int i : a)
			l.add(i);
		Collections.sort(l);
		for (int i = 0; i < a.length; i++)
			a[i] = l.get(i);
	}

	public static int lowerBound(ArrayList<Integer> array, int length, long value) {
		int low = 0;
		int high = length;
		while (low < high) {
			final int mid = (low + high) / 2;
			if (value <= array.get(mid)) {
				high = mid;
			} else {
				low = mid + 1;
			}
		}
		return low;
	}

	static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		int nextInt() {
			return Integer.parseInt(next());
		}

		long nextLong() {
			return Long.parseLong(next());
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}

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

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

	static long gcd(long a, long b) {
		if (a == 0)
			return b;
		return gcd(b % a, a);
	}

	static long lcm(long a, long b) {
		return (a * b) / gcd(a, b);
	}

	public static void sortbyColumn(int[][] att, int col) {
		// Using built-in sort function Arrays.sort
		Arrays.sort(att, new Comparator<int[]>() {

			@Override
			// Compare values according to columns
			public int compare(final int[] entry1, final int[] entry2) {

				// To sort in descending order revert
				// the '>' Operator
				// if (entry1[col] > entry2[col])
				// return 1;
				// else //(entry1[col] >= entry2[col])
				// return -1;
				return new Integer(entry1[col]).compareTo(entry2[col]);
				// return entry1[col].
			}
		}); // End of function call sort().
	}

	public static void sortbyColumn(double[][] att, int col) {
		// Using built-in sort function Arrays.sort
		Arrays.sort(att, new Comparator<double[]>() {

			@Override
			// Compare values according to columns
			public int compare(final double[] entry1, final double[] entry2) {

				// To sort in descending order revert
				// the '>' Operator
				// if (entry1[col] > entry2[col])
				// return 1;
				// else //(entry1[col] >= entry2[col])
				// return -1;
				return new Double(entry1[col]).compareTo(entry2[col]);
				// return entry1[col].
			}
		}); // End of function call sort().
	}

	static class pair {
		int V, I;

		pair(int v, int i) {
			V = v;
			I = i;
		}
	}

	public static int[] swap(int data[], int left, int right) {
		int temp = data[left];
		data[left] = data[right];
		data[right] = temp;
		return data;
	}

	public static int[] reverse(int data[], int left, int right) {
		while (left < right) {
			int temp = data[left];
			data[left++] = data[right];
			data[right--] = temp;
		}
		return data;
	}

	public static boolean findNextPermutation(int data[]) {
		if (data.length <= 1)
			return false;

		int last = data.length - 2;
		while (last >= 0) {
			if (data[last] < data[last + 1]) {
				break;
			}
			last--;
		}
		if (last < 0)
			return false;

		int nextGreater = data.length - 1;
		for (int i = data.length - 1; i > last; i--) {
			if (data[i] > data[last]) {
				nextGreater = i;
				break;
			}
		}
		data = swap(data, nextGreater, last);
		data = reverse(data, last + 1, data.length - 1);
		return true;
	}

	static long ncr(long a, long b) {
		if (b > a - b)
			return ncr(a, a - b);
		long ansMul = 1;
		long ansDiv = 1;
		for (int i = 0; i < b; i++) {
			ansMul *= (a - i);
			ansDiv *= (i + 1);
			ansMul %= MOD;
			ansDiv %= MOD;
		}

		long ans = ansMul * power(ansDiv, MOD - 2, MOD) % MOD;

		return ans;
	}

	static long __gcd(long n1, long n2) {
		long gcd = 1;

		for (int i = 1; i <= n1 && i <= n2; ++i) {
			// Checks if i is factor of both integers
			if (n1 % i == 0 && n2 % i == 0) {
				gcd = i;
			}
		}
		return gcd;
	}

	static long power(long prev, long n2, long mod2) {
		long res = 1;

		prev = prev % mod2;

		if (prev == 0)
			return 0;
		while (n2 > 0) {

			if ((n2 & 1) == 1)
				res = (res * prev) % mod2;

			n2 = n2 >> 1;
			prev = (prev * prev) % mod2;
		}
		return res;
	}

	static long modInverse(long fac2, int p) {
		return power(fac2, p - 2, p);
	}

	static boolean isPrime(int n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;

		// This is checked so that we can skip
		// middle five numbers in below loop
		if (n % 2 == 0 || n % 3 == 0)
			return false;

		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;

		return true;
	}

	public static BigInteger lcmm(String a, String b) {
		BigInteger s = new BigInteger(a);
		BigInteger s1 = new BigInteger(b);
		BigInteger mul = s.multiply(s1);
		BigInteger gcd = s.gcd(s1);
		BigInteger lcm = mul.divide(gcd);
		return lcm;
	}
	/*
	 * static boolean prime[] = new boolean[10000007]; static int spf[] = new
	 * int[10000007];
	 * 
	 * public static void sieveOfEratosthenes(int n) { for (int i = 2; i < n;
	 * i++) prime[i] = true; for (int p = 2; p * p <= n; p++) {
	 * 
	 * if (prime[p] == true) {
	 * 
	 * for (int i = p * p; i <= n; i += p) { prime[i] = false; spf[i] = p; } } }
	 * }
	 */
}