import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String[] in = new String[2];
		for (int i = 0; i < 2; i++) in[i] = sc.next();
		
		String[] weatherForecast = in[0].split("");
		String[] weather = in[1].split("");
		int count = 0;

		for (int i = 0; i < weatherForecast.length; i++) {
			if (weatherForecast[i].equals(weather[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