1 #include <bits/stdc++.h>
2 using namespace std;
3 const int m=6000;
4 int f[1010][m*2+2],n,a[2000],b[2000],k;
5 int main() {
6 memset(f, 0x3f, sizeof(f));
7 scanf("%d", &n);
8 f[0][m] = 0;
9 for (int i = 1; i <= n; i++) {
10 scanf("%d%d", &a[i], &b[i]);
11 }
12 for (int i = 1; i <= n; i++) {
13 for (int j = 1; j <= m * 2; j++) {
14 f[i][j] = min(f[i - 1][j - a[i] + b[i]], f[i - 1][j + a[i] - b[i]] + 1);
15 }
16 }
17 k = 0;
18 if (f[n][m + k] == f[0][1] && f[n][m - k] == f[0][1]) {
19 k++;
20 }
21 printf("%d\n", min(f[n][m + k], f[n][m - k]));
22 }
