#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const ll N = 1e18 + 5;

ll a[100];
ll b[100];
ll c[100];
void solve() {
    ll a0 = 1, n, a1, a2, i, ci, ans = 0, cii = 0, fl = 0, mal = 0;
    ll n11, tp;
    n11 = 0;
    //	cout<<109*15;
    //	cout<<N;
    cin >> n;
    for (i = 0; i < n; i++) {
        cin >> tp;
        // tp = 999;
        cii = 0;
        if (tp < 0) {
            tp = -tp;
            while (tp) {
                b[cii] += tp % 10;
                a1 = cii;

                while (b[a1] > 9) {
                    b[a1 + 1] += b[a1] / 10;
                    b[a1] = b[a1] % 10;
                    a1++;
                }

                tp = tp / 10;
                cii++;
            }
        } else {
            while (tp) {
                a[cii] += tp % 10;
                a1 = cii;

                while (a[a1] > 9) {
                    a[a1 + 1] += a[a1] / 10;
                    a[a1] = a[a1] % 10;
                    a1++;
                }

                tp = tp / 10;
                cii++;
            }
        }
    }

    for (i = 100; i > -1; i--) {
        if (a[i] < b[i]) {
            a0 = 0;
            break;
        } else if (a[i] > b[i]) {
            break;
        }
    }
    if (a0) {
        for (i = 0; i < 100; i++) {
            a[i] -= b[i];
            cii = i;
            while (a[cii] < 0) {
                a[cii] += 10;
                a[cii + 1] -= 1;
                cii++;
            }
        }
        for (i = 100; i > -1; i--) {
            if (a[i] != 0 || fl) {
                cout << a[i];
                fl = 1;
            }
            if (fl == 0 && a[i] == 0 && i == 0)
                cout << 0;
        }
    } else {
        for (i = 0; i < 100; i++) {
            b[i] -= a[i];
            cii = i;
            while (b[cii] < 0) {
                b[cii] += 10;
                b[cii + 1] -= 1;
                cii++;
            }
        }
        cout << "-";
        for (i = 100; i > -1; i--) {
            if (b[i] != 0 || fl) {
                cout << b[i];
                fl = 1;
            }
        }
    }
}

int main() {
    int t = 1;
    //    cin>>t;
    while (t--) {
        solve();
    }
    return 0;
}