import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		String S, T;
		int count= 0;
		Scanner scan = new Scanner(System.in);
		S=scan.nextLine();
		T=scan.nextLine();
		for (int i= 0; i<S.length();i++) {
			if(S.charAt(i)==T.charAt(i)) {
				++count;
			}
		}
		System.out.println(count);

	}

}
/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