import java.util.*;
public class Main {
        public static void main(String[] args){
                Scanner sc = new Scanner(System.in);
                // 整数の入力
                String y = sc.next();
                String j = sc.next();

                int result = 0;
                for (int i = 0; i < y.length(); i++) {
                        if (y.charAt(i) == j.charAt(i)) {
                                result += 1;
                        }
                }

                // 出力
                System.out.println(result);
        }
}
/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