#include <bits/stdc++.h>
using namespace std;
const int MAXN = 110;
int n, a[MAXN], b[MAXN];
pair <int, int> c[MAXN];
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
freopen("text.inp", "r", stdin);
freopen("text.out", "w", stdout);
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
c[i] = {a[i], b[i]};
}
sort(c + 1, c + 1 + n);
int res = 0;
for (int i = 1; i <= n; i++) {
if (res < c[i].first) res = c[i].first + c[i].second;
else res += c[i].second;
}
cout << res;
return 0;
}
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