1 #include <stdio.h>
 2 
 3 #define MAXN 100005
 4 
 5 int wi[MAXN], li[MAXN];
 6 int diff[MAXN<<1];
 7 
 8 int main() {
 9     int n, total, max;
10     int i, tmp;
11 
12     while (scanf("%d", &n) != EOF) {
13         for (i=0; i<n; ++i) {
14             scanf("%d %d", &wi[i], &li[i]);
15             diff[i] = diff[i+n] = wi[i]-li[i];
16         }
17         total = max = tmp = 0;
18         for (i=0; i<n+n; ++i) {
19             if (diff[i]>=0 || total+diff[i]>=0) {
20                 total += diff[i];
21                 ++tmp;
22             } else {
23                 if (tmp > max)
24                     max = tmp;
25                 tmp = 0;
26                 total = 0;
27             }
28         }
29         if (tmp && tmp>max)
30             max = tmp;
31         if (max > n)
32             max = n;
33         printf("%d\n", max);
34     }
35 
36     return 0;
37 }