import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String str1 = sc.next();
		String str2 = sc.next();
		int con=0;

		for (int i = 0; i < str1.length(); i++) {
			char c1 = str1.charAt(i);
			char c2 = str2.charAt(i);
			if (c1 == c2) {
				con++;
			}
		}
		System.out.println(con);
	}

}
/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