import java.util.*;
public class Main {
	public static void main(String args[]){
		Scanner sc=new Scanner(System.in);
		String a=sc.next();
		String b=sc.next();
		int n=0;
		for(int i=0;i<3;i++){
			if(a.charAt(i)==b.charAt(i)){
				n=n+1;
			}
		}
		System.out.print(n);
		
	}
}

/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