#include <iostream>
#include <string>
#include <algorithm>
//#include <gtest/gtest.h>

using std::string;

int editDistance(const string &A, const string &B) {
	int m = B.length();
	int n = A.length();
	int D[n + 1][m + 1];

	for (int i = 0; i < n + 1; i++) {
		D[i][0] = i;
	}
	for (int j = 0; j < m + 1; j++) {
		D[0][j] = j;
	}

	for (int j = 1; j < m + 1; j++) {
		for (int i = 1; i < n + 1; i++) {
			int insertion = D[i][j - 1] + 1;
			int deletion = D[i - 1][j] + 1;
			int match = D[i - 1][j - 1];
			int mismatch = D[i - 1][j - 1] + 1;
			if (A.at(i - 1) == B.at(j - 1)) {
				D[i][j] = std::min(insertion, std::min(deletion, match));
			} else {
				D[i][j] = std::min(insertion, std::min(deletion, mismatch));
			}
		}
	}

	return D[n][m];
}

//TEST(EditDistance, d2) {
//	ASSERT_EQ(0, editDistance("ab", "ab"));
//}
//TEST(EditDistance, d1) {
//	ASSERT_EQ(1, editDistance("a", "x"));
//}
//
//TEST(EditDistance, d3) {
//	ASSERT_EQ(3, editDistance("short", "ports"));
//}
//
//TEST(EditDistance, d4) {
//	ASSERT_EQ(5, editDistance("editing", "distance"));
//}

int main() {
	string str1;
	string str2;
	std::cin >> str1 >> str2;
	std::cout << editDistance(str1, str2) << std::endl;
	return 0;
}