import java.io.*;
import java.util.*;

class Main {

    // Generated by 1.1.5 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
    public static void main(String[] args) throws Exception {
        final Scanner sc = new Scanner(System.in);
        String S;
        S = sc.next();
        String T;
        T = sc.next();
        solve(S, T);
    }

    static void solve(String S, String T){
        int ans = 0;
        for (int i = 0; i < S.length(); ++i) {
            if (S.charAt(i) == T.charAt(i)) ans++;
        }
        System.out.println(ans);
    }
}

/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