import java.util.*;
class Main{
    public static void main(String[] args){
	Scanner stdIn = new Scanner(System.in);
        String S = stdIn.next();
	String T = stdIn.next();
	int count=0;
	for(int i=0;i<S.length();i++){
	    char s=S.charAt(i);
	    char t=T.charAt(i);
	    if(s==t){
		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