#include<bits/stdc++.h>
#define int long long
using namespace std;
int n, a[1005], l, r, sum, cnt, k, dp[10005], maxn = 1e18;
bool flag, f[1005];
signed main(){
    memset(dp, 0x3f, sizeof(dp));
    cin >> n;
    for(int i = 1 ; i <= n ; i++){
        cin >> l >> r;
        a[i] = abs(l - r) * 2;
        if(l > r) f[i] = 1;
        sum += l;
        cnt += r;
    }
    k = abs(sum - cnt);
    if(sum > cnt) flag = 1;
    dp[k] = 0;
    for(int i = 1 ; i <= n ; i++){
        if(f[i] == flag){
            for(int j = k ; j >= a[i] ; j--){
                dp[j - a[i]] = min(dp[j - a[i]], dp[j] + 1);
```cpp