import java.io.*;

public class FractionalKnapsack {

    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        System.out.println("Enter number of items:");
        int itemCount = Integer.parseInt(reader.readLine());

        int[] profitArray = new int[itemCount];  // profit of each item
        int[] weightArray = new int[itemCount];  // weight of each item

        // Read profit and weight for each item
        for (int i = 0; i < itemCount; i++) {
            System.out.println("Enter Profit of item " + (i + 1) + ":");
            profitArray[i] = Integer.parseInt(reader.readLine());
            System.out.println("Enter Weight of item " + (i + 1) + ":");
            weightArray[i] = Integer.parseInt(reader.readLine());
        }

        System.out.println("Enter knapsack capacity:");
        int remainingCapacity = Integer.parseInt(reader.readLine());

        // Compute profit-per-unit-weight ratio for each item
        float[] profitPerWeight = new float[itemCount];
        for (int i = 0; i < itemCount; i++) {
            profitPerWeight[i] = (float) profitArray[i] / weightArray[i];
        }

        // Sort items in descending order of profit-per-unit-weight (selection sort)
        for (int i = 0; i < itemCount; i++) {
            for (int j = i; j < itemCount; j++) {
                if (profitPerWeight[i] < profitPerWeight[j]) {
                    // Swap profit-per-weight ratios
                    float tempRatio   = profitPerWeight[i];
                    profitPerWeight[i] = profitPerWeight[j];
                    profitPerWeight[j] = tempRatio;

                    // Swap corresponding profits
                    int tempProfit   = profitArray[i];
                    profitArray[i]   = profitArray[j];
                    profitArray[j]   = tempProfit;

                    // Swap corresponding weights
                    int tempWeight   = weightArray[i];
                    weightArray[i]   = weightArray[j];
                    weightArray[j]   = tempWeight;
                }
            }
        }

        // Greedily fill the knapsack
        float totalProfit      = 0;
        float[] fractionTaken  = new float[itemCount];  // fraction of each item selected

        for (int i = 0; i < itemCount; i++) {
            if (remainingCapacity - weightArray[i] >= 0) {
                // Whole item fits: take it entirely
                remainingCapacity -= weightArray[i];
                totalProfit       += profitArray[i];
                fractionTaken[i]   = 1;
            } else if (remainingCapacity != 0) {
                // Only a fraction fits: take what we can
                float fraction    = (float) remainingCapacity / weightArray[i];
                totalProfit      += profitArray[i] * fraction;
                fractionTaken[i]  = fraction;
                break;  // knapsack is now full
            } else {
                break;  // no remaining capacity
            }
        }

        System.out.println("Maximum Profit: " + totalProfit);
    }
}