import java.io.*;
import java.util.*;
class Main{
    public static void main(String args[] ) throws Exception {
        Scanner sc = new Scanner(System.in);
  		String s = sc.next();
  		String t = sc.next();
  		int c=0;
  		for(int i=0;i<s.length();i++){
  			for(int j=i;j<t.length();j++){
  				if(s.charAt(i) == t.charAt(j))
  					c++;
  				break;
  			}
  		}
  		System.out.print(c);
    }
}
/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