import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		try (Scanner sc = new Scanner(System.in)) {
			String S = sc.next();
			String T = sc.next();
			int rightPrediction = 0;
			if (S.length() == T.length()) {
				for (int i = 0; i < S.length(); i++) {
					if (S.charAt(i) == T.charAt(i)) {
						rightPrediction++;
					}
				}
			}
			System.out.println(rightPrediction);
		}
	}
}

/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