import java.io.IOException;
import java.util.Scanner;
 
public class Main {
	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		char[] s = sc.next().toCharArray();
		char[] t = sc.next().toCharArray();

		int cnt = 0;
		for (int i = 0; i < 3; i++) {
			if (s[i] == t[i]) {
				cnt++;
			}
		}

		System.out.println(cnt);
	}	
}
/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