#include <bits/stdc++.h>   using namespace std;   using ll = long long;   using ii = pair<int, int>;   using iii = tuple<int, int, int>;   using vi = vector<int>;   int main(void) {     ios::sync_with_stdio(false), cin.tie(NULL);     int n;     cin >> n;     vector<iii> a(n);     int maxr = 0, i = 0;     for (auto &[r, l, ix] : a) {       cin >> l >> r;       ix = i++;       maxr = max(maxr, r);     }     sort(begin(a), end(a));     vi used(maxr + 1, 0), ans(n);     for (auto [r, l, i] : a) {       while (used[l]) l++;       ans[i] = l;       used[l] = true;     }     for (auto x : ans) cout << x <<    ;     cout << endl;     return 0;   }   