#include using namespace std; #define fst(t) std::get<0>(t) #define snd(t) std::get<1>(t) #define thd(t) std::get<2>(t) #define unless(p) if(!(p)) #define until(p) while(!(p)) using ll = long long; using P = std::tuple; const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1}; char c[3]; int d[3], q; bool can(int n){ d[q] = n; return *max_element(d, d+3) == n || *min_element(d, d+3) == n; } int main(){ std::cin.tie(nullptr); std::ios::sync_with_stdio(false); scanf("%c %c %c", c, c + 1, c + 2); for(int i=0;i<3;++i){ if(c[i] == '?'){q = i;} else{d[i] = c[i] - '0';} } string res = ""; if(can(1)){res += "1";} if(can(4)){res += "4";} std::cout << res << std::endl; }