import java.util.Scanner;

class Main {

	public static void main(String[] args) {
		Scanner ipt = new Scanner(System.in);
		//1
		String n = ipt.next();
		String[] alpha = null;
		String[] alpha2 = null;
		int ans = 0;
		alpha = n.split("");
		//2
		n = ipt.next();
		alpha2 = n.split("");
		for (int i = 0; i < alpha.length; i++) {
			if (alpha[i].equals(alpha2[i])) {
				ans++;
			}
		}
		System.out.println(ans);
		ipt.close();
	}
}
/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