#include <stdio.h>

int main()
{
	char S[100001];
	scanf("%s", S);

	int i, j, k, dp[27], l, r, m;
	for (i = 0, dp[0] = 0, k = 0; S[i] != 0; i++) {
		if (S[i] == '?') continue;
		l = 0;
		r = k + 1;
		while (l < r) {
			m = (l + r) / 2;
			if (dp[m] < S[i] - 'a' + 1) l = m + 1;
			else r = m;
		}
		dp[l] = S[i] - 'a' + 1;
		if (l > k) k++;
	}
	if (k == 0) {
		for (i = 0; S[i] != 0; i++) printf("a");
		printf("\n");
		fflush(stdout);
		return 0;
	}
	
	for (i--, dp[0] = 30, j = 0; i >= 0; i--) {
		if (S[i] == '?') {
			if (j < k) S[i] = 'a';
			else S[i] = 'a' + dp[j] - 1;
		} else {
			l = 0;
			r = j + 1;
			while (l < r) {
				m = (l + r) / 2;
				if (dp[m] > S[i] - 'a' + 1) l = m + 1;
				else r = m;
			}
			dp[l] = S[i] - 'a' + 1;
			if (l > j) j++;
		}
	}
	printf("%s\n", S);
	fflush(stdout);
	return 0;
}