#include <bits/stdc++.h>

using namespace std;

class Solution {
public:
    int longestCommonSubsequence(string text1, string text2) {
        int m = text1.size();
        int n = text2.size();
        vector< vector<int>> dp(m+1, vector<int> (n+1,-1));   
        for(int i = 0; i <= m; ++i) {
            for(int j = 0; j <= n; ++j) {
                if(i == 0 || j == 0) {
                    dp[i][j] = 0;
                } else {
                    if(text1[i-1] == text2[j-1]) {
                          dp[i][j] = 1 + dp[i-1][j-1];
                    } else {
                          dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
                    }
                }
            }
        }
        return dp[m][n];
    }
};
int main() {
Solution lcs;
string text1 = "abdr";
string text2 = "acdr"; int ans = lcs.longestCommonSubsequence(text1,text2);

cout<<ans;
}