#include <bits/stdc++.h>

#define el '\n'
#define Beevo ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

typedef long long ll;
typedef long double ld;

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

void testCase() {
    string a, b, c, d;
    cin >> a >> b >> c >> d;

    if (isdigit(a[0]) && isdigit(d[0]))
        cout << stoi(a) + stoi(d) - 1;
    else if (isdigit(a[0]) && isdigit(c[0]))
        cout << max(stoi(a), stoi(c)) - min(stoi(a), stoi(c));
    else if (isdigit(b[0]) && isdigit(d[0]))
        cout << max(stoi(b), stoi(d)) - min(stoi(b), stoi(d));
    else
        cout << stoi(b) + stoi(c) - 1;
}

signed main() {
    Beevo

    int t = 1;
//    cin >> t;

    while (t--)
        testCase();
}