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#include <bits/stdc++.h>
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using namespace std;
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int main() {
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    int q;
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    cin >> q;
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    map<string, int> mp;
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    for (int i = 0; i < q; ++i) {
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        string op;
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        cin >> op;
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        if (op == "+") {
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            string name;
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            int val;
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            cin >> name >> val;
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            mp[name] += val;
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        } else if (op == "-") {
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            string name;
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            int val;
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            cin >> name >> val;
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            mp[name] -= val;
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        } else {
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            string name;
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            cin >> name;
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            if (mp.find(name) != mp.end()) {
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                cout << mp[name] << endl;
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            } else {
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                cout << 0 << endl;
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            }
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        }
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    }
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    return 0;
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}
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