Go: ///
// File:  0528.go
// Author: ymiyamoto
//
// Created on Thu Mar 22 01:52:09 2018
//
package main

import (
	"bufio"
	"fmt"
	"os"
)

var S, T string
var dp [4001][4001]int

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	for {
		scanner.Scan()
		S = scanner.Text()
		if len(S) == 0 {
			return
		}

		scanner.Scan()
		T = scanner.Text()

		for i := range dp {
			for j := range dp[i] {
				dp[i][j] = 0
			}
		}

		dp[0][0] = 0
		for i := range S {
			for j := range T {
				if S[i] == T[j] {
					dp[i+1][j+1] = max(dp[i+1][j], max(dp[i][j+1], dp[i][j]+1))
				} else {
					dp[i+1][j+1] = 0
				}
			}
		}
		var m int
		for i := range dp {
			for j := range dp[i] {
				m = max(m, dp[i][j])
			}
		}
		fmt.Println(m)
	}
}

C++: //JOI 0528 Common Sub-String
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	while(1){
		string s, t; int roop1=0, roop2 = 0,roop3, save[100000]={}, ans = 0;
		cin>>s;
		cin>>t;
		if(cin.eof())
		break;
	for (int i = 0; i<s.size(); i++){
		for (int j = 0; j<t.size(); j++){
			if (s[i] == t[j]){
				roop1 = 0;
				save[roop2] = 0;
				while (1){
					if (s[i + roop1] == 0 || t[j + roop1] == 0){
						break;
					}
					else{
						if (s[i + roop1] == t[j + roop1]){
							save[roop2] += 1;
							roop1++;
						}
						else if (s[i + roop1] != t[j + roop1]){
							roop2++;
							break;
						}
					}
				}
			}
		}
	}
	sort(save, save + roop2 + 1);
	ans = save[roop2];
	cout << ans << endl;
	}
	return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define all(a)  (a).begin(),(a).end()
#define vi vector<int>
#define pb push_back
#define INF 999999999

#define MAX_S 4000
#define MAX_T 4000
template<typename T> int longest_common_substring(T s,T t){
    int lens=s.size(), lent=t.size();
    static int dp[MAX_S+1][MAX_T+1];
    rep(i,MAX_S+1)rep(j,MAX_T+1)dp[i][j]=0;
    
    int maxi=0;
    
    rep(i,s.size()){
        rep(j,t.size()){
            if(s[i]==t[j])  dp[i+1][j+1] = dp[i][j]+1;
            else            dp[i+1][j+1] = 0;
            maxi = max(maxi,dp[i+1][j+1]);
        }
    }
    
    return maxi;
}


int main(){
    string a,b;
    while(cin>>a>>b){
        cout<<longest_common_substring(a,b)<<endl;
    }
}

C++: #include<bits/stdc++.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define show(x)  cerr << #x << " = " << (x) << endl;
//const int INF = 1e8;
using namespace std;

const int MAX_N = 4005;
int dp[MAX_N + 1][MAX_N + 1];
string s, t;

int solve(){
    int n = s.size(), m = t.size(); //????????°?????±?????¨?????????????????????
    rep(i,MAX_N) rep(j,MAX_N) dp[i][j] = 0;

    rep(i,n){
        rep(j,m){
            if(s[i] == t[j]){
                dp[i + 1][j + 1] = dp[i][j] + 1;
            }
            //jelse{
            //j    dp[i + 1][j + 1] = min(dp[i][j + 1], dp[i + 1][j]);
            //j}
        }
    }

    int sum = 0;
    rep(i,n){
        rep(j,m){
            sum = max(sum,dp[i][j]);
        }
    }
    return sum;
}

int main(){
    while(cin >> s >> t){
        cout << solve() << endl;
    }
}

C++: #include <algorithm>
#include <bitset>
#include <cstdio>
#include <cstring>
#include <cassert>
#include <cmath>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

typedef long long LL;
typedef pair<int, int> P;
typedef pair<LL, LL> PLL;

int dp[4000][4000];

int main() {
    string s, t;
    while (cin >> s >> t) {
        for (int j = 0; j < 4000; ++j) {
            fill(dp[j], dp[j] + 4000, 0);
        }

        int ret = 0;

        for (int j = 0; j < s.size(); ++j) {
            for (int k = 0; k < t.size(); ++k) {
                if (s[j] != t[k]) {
                    dp[j][k] = 0;
                } else if (j == 0 || k == 0) {
                    dp[j][k] = 1;
                } else {
                    dp[j][k] = dp[j-1][k-1] + 1;
                }

                ret = max(ret, dp[j][k]);
            }
        }

        cout << ret << endl;
    }
    return 0;
}

C++: //JOI 0528 Common Sub-String
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	string s, t;
	for(int o=0;o<3;o++){
                cin>>s>>t;
		int roop1=0, save=0, ans = 0;
	for (int i = 0; i<s.size(); i++){
		for (int j = 0; j<t.size(); j++){
			if (s[i] == t[j]){
				roop1 = 0;
				save= 0;
				while (1){
						if (s[i + roop1] == t[j + roop1]){
							save += 1;
							roop1++;
						}
					else if (s[i + roop1] != t[j + roop1]){
							ans=max(ans,save);
							break;
					}
				}
			}
		}
	}
	cout<<ans<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	string s, t;
	while(1){
		cin >> s >> t;
		if(cin.eof()) { break; }
		
		int ans = 0, c = 0;;
		for(size_t i = 0; i < s.size(); ++i){
			for(size_t j = 0; j < t.size(); ++j){
				if(s[i] == t[j]){
					c = 1;
					while(s[i + c] == t[j + c]){
						c++;
					}
					ans = max(ans, c);
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int dp[4001][4001];

int main()
{
    string s,t;
    while(cin >> s) {
        cin >> t;
        int ret = 0;

        for(int off = -(int)s.size(); off <= (int)t.size(); off++) {
            int len = 0;
            for(int i = max(off, 0); i < min(s.size() + off, t.size()); i++) {
                if(len > ret)
                    ret = len;
                
                if(s[i - off] == t[i])
                    len++;
                else
                    len = 0;
            }
        }
        cout << ret << endl;
    }
}

C++: #include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <map>
#include <queue>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <stack>
typedef long long int lli;
using namespace std;

/*
int main(){
	int n,k;
	while(cin>>n>>k&&n!=0&&k!=0){
		vector<int> card(n+1);
		vector<int> flag(n+1);
		flag[0]=-1;
		card[0]=-1;
		for(int i=0;i<k; ++i){
			int tmp;
			cin >> tmp;
			card[tmp]=tmp;
			flag[tmp]=1;
		}
		int ans=0;
		if(flag[0]!=0){
			int cnt=0;
			int s;
			int n;
			for(int i=1;i<=n; ++i){
				if()
			}
		}
	}
	return 0;
}*/

int main(){
	string A,B;
	while(cin>>A>>B){
		int ans=0;
		for(int i=0; i<A.size(); ++i){
			for(int j=1; i+j<A.size(); ++j){
				string tmp=A.substr(i,j);
				/*for(int k=i;k<j; ++k){
					tmp+=A[k];
				}*/
				int a=tmp.size();
				if(B.find(tmp)!=-1) ans=max(ans,a);
			}
		}
		cout << ans << "\n";
	}
	return 0;
}

C++: //JOI 0528 Common Sub-String
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	while(1){
		string s, t; int roop1=0, roop2 = 0, save[6500000]={}, ans = 0;
		cin>>s;
		cin>>t;
		if(cin.eof())
		break;
	for (int i = 0; i<s.size(); i++){
		for (int j = 0; j<t.size(); j++){
			if (s[i] == t[j]){
				roop1 = 0;
				save[roop2] = 0;
				while (1){
					if (s[i + roop1] == 0 || t[j + roop1] == 0){
						break;
					}
					else{
						if (s[i + roop1] == t[j + roop1]){
							save[roop2] += 1;
							roop1++;
						}
						else if (s[i + roop1] != t[j + roop1]){
							roop2++;
							break;
						}
					}
				}
			}
		}
	}
	sort(save, save + roop2 + 1);
	ans = save[roop2];
	cout << ans << endl;
	}
	return 0;
}