import java.util.Scanner;

class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		String t = sc.next();
		sc.close();
		char[] c1 = s.toCharArray();
		char[] c2 = t.toCharArray();
		int ans = 0;
		for (int i = 0; i < s.length(); i++)
			if (c1[i] == c2[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