import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        String str1 = sc.next();
        char[] c1 = str1.toCharArray();
        String str2 = sc.next();
        char[] c2 = str2.toCharArray();
        
        int count = 0;
        int n = c1.length;
        for (int i = 0; i < n; i++) {
            if (c1[i] == c2[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