import java.util.Scanner;

public class Main {

	public static final long CONST = 100000007L;

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String strS = scan.next();
		String strT = scan.next();

		int count = 0;

		for (int i = 0; i < 3; i++) {
			if ((strS.substring(i, i+1)).equals(strT.substring(i, i+1))) {
				count++;
			}
		}
		System.out.println(count);
	}
}

/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