import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);

		String n = scan.nextLine();
		String m = scan.nextLine();

		char[] a = n.toCharArray();
		char[] b = m.toCharArray();

		int total = 0;

		for(int i=0;i<3;i++) {
			if(a[i]==b[i]) {
				total+=1;
			}
		}

		System.out.println(total);

	}

}
/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