import java.util.*;

public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    String  S = sc.next();
    String  T = sc.next();    

    char[] s = S.toCharArray();
    char[] t = T.toCharArray();

    int cou = 0;
    for(int i=0; i<3; i++){
	if(s[i]==t[i]){
	    cou++;
	}
    }
		System.out.println(cou);
	}
}
/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