import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.stdio;
import std.string;
import std.range;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

int calc(int x, int y, int gx, int gy) {
    int ans = max(x, y);
    if (x == y && gx == gy && gx < x) {
        ans++;
    }
    return ans;
}

void main() {
    auto xs = readints();
    auto ys = readints();
    writeln(calc(xs[0], xs[1], ys[0], ys[1]));
}