import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) {
		try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
			String[] ss = br.readLine().split(" ");
			for(int i=0; i<ss.length; i++) {
				if(ss[i].equals("0")) {
					System.out.print(i+1);
				}
			}
		} catch(Exception e) {}
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz