import java.util.Scanner;
public class Main {
	public static void main(String argsp[]){
		Scanner sc = new Scanner(System.in);
		int a = 0;
		String s = sc.next(), t = sc.next();
		for(int i = 0; i< 3; i++){
			if(s.charAt(i) == t.charAt(i)){
				a++;
			}
		}
		System.out.print(a);
	}
}
/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