#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	string c[3];
	REP(i, 3) cin >> c[i];
	int p;
	REP(i, 3) if (c[i] == "?") p = i;
	auto func = [&](int n) -> bool {
		c[p][0] = n + '0';
		if (c[0] > c[1] && c[1] < c[2]) return true;
		if (c[0] < c[1] && c[1] > c[2]) return true;
		return false;
	};
	for (int i : {1, 4}) if (func(i)) putchar(i + '0');
	putchar('\n');
}