#include <iostream>
using namespace std;

int calculate_bill(int kWh) {
    int total_cost = 0;

    // Tier 1: First 100 kWh
    if (kWh > 0) {
        int tier1 = (kWh > 100) ? 100 : kWh;
        total_cost += tier1 * 2000;
        kWh -= tier1;
    }

    // Tier 2: Next 100 kWh (101 to 200)
    if (kWh > 0) {
        int tier2 = (kWh > 100) ? 100 : kWh;
        total_cost += tier2 * 3000;
        kWh -= tier2;
    }

    // Tier 3: Next 100 kWh (201 to 300)
    if (kWh > 0) {
        int tier3 = (kWh > 100) ? 100 : kWh;
        total_cost += tier3 * 5000;
        kWh -= tier3;
    }

    // Tier 4: Beyond 300 kWh
    if (kWh > 0) {
        total_cost += kWh * 10000;
    }

    return total_cost;
}

int main() {
    int kWh;
    cin >> kWh;
    
    int result = calculate_bill(kWh);
    cout << result << endl;
    
    return 0;
}

750000