#include #include #include #include using namespace std; typedef long long ll; typedef vector vint; typedef pair pint; typedef vector vpint; #define rep(i,n) for(int i=0;i<(n);i++) #define reps(i,f,n) for(int i=(f);i<(n);i++) #define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++) #define all(v) (v).begin(),(v).end() #define pb push_back #define mp make_pair #define fi first #define se second #define chmax(a, b) a = (((a)<(b)) ? (b) : (a)) #define chmin(a, b) a = (((a)>(b)) ? (b) : (a)) const int MOD = 1e9 + 7; const int INF = 1e9; int main(void){ int x, y, x2, y2; cin >> x >> y >> x2 >> y2; int ans = max(x, y); //x >= 0 y >= 0 if(x == y && x2 == y2){ printf("%d\n", ans + 1); }else{ printf("%d\n", ans); } return 0; }