Task B

#include <iostream>
#define int int64_t

using namespace std;

int32_t main()
{
    int n;
    cin >> n;
    int a[n];
    for(auto &i: a)
        cin >> i;
    int f = 1, s = a[0];
    for(int i = 1; i < n; i++){
        cout << f << ' ' << s << '\n';
        f = s + 1;
        s = f + a[i] - 1;
    }
    cout << f << ' ' << s << '\n';
}