#include <stdio.h>

#define NMAX 40000

int main(void) {
  int n, h, w;
  int ss; // stack size
  int sh[NMAX + 2], end[NMAX + 2]; // height and endpoint of stack rectangles; sentinels at both ends
  long long maxArea = 0;

  FILE *f = fopen("skyline.in", "rt");
  fscanf(f, "%d", &n);

  sh[0] = end[0] = 0;
  ss = 1;

  for (int i = 0; i <= n ; i++) {
    // Force a 0-height rectangle at the end to empty the stack.
    if (i == n) {
      h = w = 0;
    } else {
      fscanf(f, "%d %d", &h, &w);
    }

    // Pop taller rectangles from the stack.
    // Their left coordinate is the endpoint of the previous rectangle on the stack.
    // Their right coordinate is the endpoint of the top of the stack.
    int endpoint = end[ss - 1];
    while (sh[ss - 1] > h) {
      long long area = (long long)sh[ss - 1] * (endpoint - end[ss - 2]);
      if (area > maxArea) {
        maxArea = area;
      }
      // printf("rectangle of height %d starts at %d and ends at %d area %lld\n", sh[ss - 1], end[ss - 2], endpoint, area);
      ss--;
    }

    // Push the new rectangle on the stack.
    sh[ss] = h;
    end[ss] = w + endpoint;
    ss++;
  }    
  fclose(f);

  f = fopen("skyline.out", "w");
  fprintf(f, "%lld\n", maxArea);
  fclose(f);
}