Wrong Answer in BEX? What's wrong in my approach?

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Problem: [BEX][1]

My code:

#include <bits/stdc++.h>

using namespace std;

typedef long long lld;

int main() {
    lld T;
    cin >> T;
    deque<pair<string, lld>> name;
    while (T--) {
        string str;
        lld diff;
        cin >> diff;
        if (diff < 0) {
            lld idx = 0, mn = LONG_LONG_MAX;
            for (lld i = 0; i < name.size(); i++)
                if (name[i].second < mn) {
                    idx = i;
                    mn = name[i].second;
            cout << idx << " " << name[idx].first << '\n';
            name.erase(name.begin(), name.begin() + idx + 1);
        } else {
            cin >> str;
            name.emplace_front(str, diff);
    return 0;

My Approach: I have had trouble understanding the problem statement and so my approach might be wrong too. What I do is, I input all values until -1 is hit. Then I check for the minimum value in the array and calculate the number of books required to remove above it. I assume that this value is going to be equal to the index of the book in the pile. In doing so, I remove all the books from above, including the solved book.
[1]: https://www.codechef.com/problems/BEX

Some books that are picked up do not get placed on the pile. Read the problem statement carefully.