import std.algorithm;
import std.array;
import std.ascii;
import std.container;
import std.conv;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

void log(A...)(A arg) {
    stderr.writeln(arg);
}
int size(T)(in T s) {
    return cast(int)s.length;
}

void main() {
    int x, y; readf("%d %d\n", &x, &y);
    int X, Y; readf("%d %d\n", &X, &Y);
    int f = (x == y && X == Y && X < x);
    int z = max(x, y);
    writeln(z + f);
}