复制
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 5010;
char s[N];
int dp[N][N], LCPS[N][N];
int pre[N][N];

int main() {
    scanf("%s", s + 1);
    int n = strlen(s + 1);
    for (int i = n; i; i -- ) {
        for (int j = n; j; j -- ) {
            if (s[i] == s[j]) LCPS[i][j] = LCPS[i + 1][j + 1] + 1;
            dp[i][j] = -1e9;
        }
    }
    dp[1][0] = 1;
    for (int i = 1; i <= n; i ++ ) {
        for (int j = i; j <= n; j ++ ) {
            if (dp[i][j - 1] > dp[i][j]) {
                dp[i][j] = dp[i][j - 1];
                pre[i][j] = pre[i][j - 1];
            }
            if (j == n) continue;
            int k = min(j - i + 1, LCPS[i][j + 1]);
            if (j + 1 + k > n) continue;
            if (i + k > j || s[i + k] < s[j + 1 + k]) {
                if (dp[i][j] + 1 > dp[j + 1][j + 1 + k]) {
                    dp[j + 1][j + 1 + k] = dp[i][j] + 1;
                    pre[j + 1][j + 1 + k] = i;
                }
            }
        }
    }
    int cnt = 0, last = 0, ed = n;
    for (int i = 1; i <= n; i ++ )
        if (dp[i][n] > cnt)
            cnt = dp[i][n], last = i;
    vector<int> ans(1, n + 1);
    while (last) {
        int t = pre[last][ed];
        ans.push_back(last);
        ed = last - 1, last = t;
    }
    reverse(ans.begin(), ans.end());
    cout << cnt << "\n";
    for (int i = 0; i + 1 < ans.size(); i ++ , cout << "\n")
        for (int j = ans[i]; j < ans[i + 1]; j ++ )
            cout << s[j];
    return 0;
}