import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String S = sc.next();
		String T = sc.next();
		
		char[] SC = S.toCharArray();
		char[] TC = T.toCharArray();
		
		int count = 0;
		for(int i=0;i<3;i++) {
			if(SC[i] == TC[i]) {
				count++;
			}
		}
		
		System.out.println(count);
		
		sc.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