import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); char[] A = in.nextLine().toCharArray(); char[] B = in.nextLine().toCharArray(); int[][] DP = new int[A.length + 1][B.length + 1]; DP[0][0] = 0; for (int i = 0; i <= A.length; i++) { for (int j = 0; j <= B.length; j++) { if (i != 0 && j != 0) { DP[i][j] = i + j; DP[i][j] = Math.min(DP[i][j], DP[i - 1][j] + 1); DP[i][j] = Math.min(DP[i][j], DP[i][j - 1] + 1); DP[i][j] = Math.min(DP[i][j], DP[i - 1][j - 1] + (A[i - 1] == B[j - 1] ? 0 : 1)); } else if (i != 0) { DP[i][j] = i; } else if (j != 0) { DP[i][j] = j; } } } System.out.println(DP[A.length][B.length]); } }