import java.util.*;

public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 998244353;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;
	int len = (int)1e6 + 1;
	
	
	void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	}
	
	
	public static void main(String[] args) {
		new Main().doIt();
	}

} import java.util.*; util.* java public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 998244353;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;
	int len = (int)1e6 + 1;
	
	
	void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	}
	
	
	public static void main(String[] args) {
		new Main().doIt();
	}

} Main Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final int MOD = 998244353; MOD 998244353 final int MAX = Integer.MAX_VALUE; MAX Integer.MAX_VALUE Integer Integer.MAX_VALUE final long LMAX = Long.MAX_VALUE; LMAX Long.MAX_VALUE Long Long.MAX_VALUE int len = (int)1e6 + 1; len (int)1e6 + 1 (int)1e6 1 void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	} doIt {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	} for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		} int i = 1; int i = 1; i 1 i <= 5 i 5 i++ i++ i {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		} {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		} if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			} sc.nextInt() == 0 sc.nextInt() sc.nextInt sc 0 {
				System.out.println(i);
				return;
			} System.out.println(i) System.out.println System.out System System.out i return; public static void main(String[] args) {
		new Main().doIt();
	} main {
		new Main().doIt();
	} new Main().doIt() new Main().doIt new Main() String[] args args public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 998244353;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;
	int len = (int)1e6 + 1;
	
	
	void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	}
	
	
	public static void main(String[] args) {
		new Main().doIt();
	}

} public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 998244353;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;
	int len = (int)1e6 + 1;
	
	
	void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	}
	
	
	public static void main(String[] args) {
		new Main().doIt();
	}

} Main
import java.util.*;

public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 998244353;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;
	int len = (int)1e6 + 1;
	
	
	void doIt() {
		for(int i = 1; i <= 5; i++) {
			if(sc.nextInt() == 0) {
				System.out.println(i);
				return;
			}
		}
	}
	
	
	public static void main(String[] args) {
		new Main().doIt();
	}

}
