#include using namespace std; using uint = unsigned int; using ll = long long; using ull = unsigned long long; template using V = vector; template using VV = V>; template using VVV = V>; template using VVVV = VV>; #define rep(i,n) for(ll i=0ll;i void chmin(T& t, const U& u) { if (t > u) t = u; } template void chmax(T& t, const U& u) { if (t < u) t = u; } // cin.tie(nullptr); // ios::sync_with_stdio(false); // cout << fixed << setprecision(20); void solve(){ string s,t; cin >> s >> t; while(s.size()t.size()) t = "0"+t; ll n = s.size(); string ans = s; VV v(10, V(10,0)); rep(i,10) rep(j,i) v[i][j] = 1; v[4][7] = 1; v[7][4] = 0; rep(i, n) if(s[i]!=t[i]){ if(v[s[i]-'0'][t[i]-'0']) break; else{ ans = t; break; } } ll cnt = 0; all(c,s){ if(c == '0') cnt++; else break; } cout << s.substr(cnt) << endl; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int t=1; // cin >> t; rep(i,t) solve(); }