#include <iostream>
using namespace std;
const int MAX_SIZE = 100000;
int main() {
int n, v[MAX_SIZE + 1], lost = 0;
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> v[i];
lost += v[i];
}
for (int j = 1; j <= n - 1; ++j) {
cin >> v[j];
lost -= v[j];
}
cout << lost;
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKY29uc3QgaW50IE1BWF9TSVpFID0gMTAwMDAwOwoKaW50IG1haW4oKSB7CglpbnQgbiwgdltNQVhfU0laRSArIDFdLCBsb3N0ID0gMDsKCWNpbiA+PiBuOwoJZm9yIChpbnQgaSA9IDE7IGkgPD0gbjsgKytpKSB7CgkJY2luID4+IHZbaV07CgkJbG9zdCArPSB2W2ldOwoJfQoJZm9yIChpbnQgaiA9IDE7IGogPD0gbiAtIDE7ICsraikgewoJCWNpbiA+PiB2W2pdOwoJCWxvc3QgLT0gdltqXTsKCX0KCWNvdXQgPDwgbG9zdDsKCXJldHVybiAwOwp9