import java.math.BigInteger;
import java.util.*;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);

		String[] S = scanner.nextLine().split("");
		String[] T = scanner.nextLine().split("");
		int ans = 0;

		for (int i = 0; i < 3; i++) {
			if (S[i].equals(T[i]))
				ans++;
		}

		System.out.println(ans);

	}

}

/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