import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;

class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner();

		int N = sc.nextInt();
		long[] C = new long[N];
		long[] D = new long[N];
		long ans = 0;
		for (int i = 0; i < N; ++i) {
			C[i] = sc.nextLong();
			D[i] = sc.nextLong();
			ans += C[i] + D[i];
		}
		class Pair implements Comparable<Pair> {
			long v;
			long min;

			public Pair(long v, long min) {
				this.v = v;
				this.min = min;
			}

			@Override
			public int compareTo(Pair o) {
				return -Long.compare(min, o.min);
			}
		}
		PriorityQueue<Pair> pq = new PriorityQueue<>();
		long pending = D[0] - C[0];
		pq.add(new Pair(D[0], C[0]));
		for (int i = 1; i < N; ++i) {
			pq.add(new Pair(D[i] + pending, C[i]));
			pending = Math.max(pending, D[i] - C[i] + pending);
			long max = -Long.MAX_VALUE / 3;
			while (!pq.isEmpty() && pq.peek().min >= C[i]) {
				Pair p = pq.poll();
				max = Math.max(max, p.v);
				pending = Math.max(max - C[i], pending);
			}
			if (max != -Long.MAX_VALUE / 3)
				pq.add(new Pair(max, C[i]));
		}
		System.out.println(ans - pending);
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}

class Scanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}

	private int readByte() {
		if (hasNextByte())
			return buffer[ptr++];
		else
			return -1;
	}

	private static boolean isPrintableChar(int c) {
		return 33 <= c && c <= 126;
	}

	private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr]))
			ptr++;
	}

	public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	}

	public String next() {
		if (!hasNext())
			throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public int nextInt() {
		return (int) nextLong();
	}

	public long nextLong() {
		if (!hasNext())
			throw new NoSuchElementException();
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
}