if let s1 = readLine(), let s2 = readLine() {
    let arr1: [Character] = Array(s1)
    let arr2: [Character] = Array(s2)
    let l1: Int = arr1.count
    let l2: Int = arr2.count
    var dp: [[Int]] = Array(repeating: Array(repeating:0, count: l2+1), count : l1+1)

    for i in 1...l1 {
        let c1: Character = arr1[i-1]
        for j in 1...l2 {
            let c2: Character = arr2[j-1]
            if c1==c2 {
                dp[i][j] = dp[i-1][j-1]+1
            }
            else {
                dp[i][j] = max(dp[i-1][j], dp[i][j-1])
            }
        }
    }
    print(dp[l1][l2])
}