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

		String a,b;
		int cnt=0;

		Scanner sc = new Scanner(System.in);

		a = sc.next();
		b = sc.next();

		for(int i = 0; i < a.length(); i++) {
			if(a.charAt(i)==b.charAt(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