#include<bits/stdc++.h>
using namespace std;
int son[2005][30], cnt, fail[2005], a[2005], f[2005][2005], from[2005][2005], ffrom[2005][2005];
string s, t;
int n, m;
void add() {
	int w = 0;
	for (int i = 0; i < n; i++) {
		if (son[w][t[i] - 'a'] != 0) {
			w = son[w][t[i] - 'a'];
		} else {
			son[w][t[i] - 'a'] = ++cnt;
			w = cnt;
		}
	}
}
void build() {
	queue<int> q;
	for (int i = 0; i < 26; i++) {
		if (son[0][i] != 0) {
			q.push(son[0][i]);
		}
	}
	while (q.size()) {
		int p = q.front();
		q.pop();
		for (int i = 0; i < 26; i++) {
			if (son[p][i] != 0) {
				fail[son[p][i]] = son[fail[p]][i];
				q.push(son[p][i]);
			} else {
				son[p][i] = son[fail[p]][i];
			}
		}
	}
}
inline void print(int p, int q) {
	if (!p) return;
	print(p - 1, from[p][q]);
	cout << char('a' + ffrom[p][q]);
}
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> s >> t;
	m = s.size(), n = t.size();
	for (int i = 1; i <= m; i++) {
		if (s[i - 1] == '?') a[i] = -1;
		else a[i] = s[i - 1] - 'a';
	}
	add();
	build();
	memset(f, -0x3f, sizeof(f));
	f[0][0] = 0;
	for (int i = 1; i <= m; i++) {
		for (int j = 0; j <= cnt; j++) {
			if (a[i] == -1) {
				for (int k = 0; k < 26; k++) {
					if (f[i - 1][j] > f[i][son[j][k]] ) {
						f[i][son[j][k]] = f[i - 1][j];
						from[i][son[j][k]] = j;
						ffrom[i][son[j][k]] = k;
					}
				}
			} else {
				if (f[i - 1][j] >	f[i][son[j][a[i]]]) {
					f[i][son[j][a[i]]] = f[i - 1][j];
					from[i][son[j][a[i]]] = j;
					ffrom[i][son[j][a[i]]] = a[i];
				}
			}
		}
		if (f[i][cnt] >= 0)f[i][cnt]++;
	}
	int ans = -1, maxb = -1;
	for (int j = 0; j <= cnt; j++) {
		if (f[m][j] > ans) {
			ans = f[m][j];
			maxb = j;
		}
	}
	cout << ans << "\n";
	print(m, maxb);
	return 0;
}