#include<bits/stdc++.h> using namespace std; using uint = unsigned int; using ll = long long; using ull = unsigned long long; template<class T> using V = vector<T>; template<class T> using VV = V<V<T>>; template<class T> using VVV = V<VV<T>>; template<class T> using VVVV = VV<VV<T>>; #define rep(i,n) for(ll i=0ll;i<n;i++) #define REP(i,a,n) for(ll i=a;i<n;i++) const long long INF = (1LL << 60); const long long mod99 = 998244353; const long long mod107 = 1000000007; const long long mod = mod99; #define eb emplace_back #define pb eb #define be(v) (v).begin(),(v).end() #define all(i,v) for(auto& i : v) #define all2(i,j,v) for(auto& [i,j] : v) template<class T, class U> void chmin(T& t, const U& u) { if (t > u) t = u; } template<class T, class U> 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(){ ll x,y; ll a,b; cin >> x >> y >> a >> b; ll ans = INF; if(x!=y || a!=b || a > x) ans = max(x, y); else ans = x+1; cout << ans << endl; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int t=1; // cin >> t; rep(i,t) solve(); }