#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int INF = 0x3f3f3f3f;int n,x;int a[1005];int b[1005];int dp[1005][6005];int abs(int a){    return a > 0 ? a : -a;}int dfs(int cur,int gap){    if(dp[cur][gap] != -1)        return dp[cur][gap];    if(cur == n)    {        return dp[cur][gap] = abs(gap);    }    int x = dfs(cur + 1,gap + a[cur] - b[cur]);    int y = dfs(cur + 1,gap + b[cur] - a[cur]);    return dp[cur][gap] = min(x, y);}int dfs2(int cur,int gap){    if(dp[cur][gap] != -1)        return dp[cur][gap];    if(cur == n)    {        if(abs(gap) == x)            return dp[cur][gap] = 0;        return dp[cur][gap] = INF;    }    int p = dfs2(cur + 1,gap + a[cur] - b[cur]);    int q = dfs2(cur + 1,gap + b[cur] - a[cur]) + 1;    return dp[cur][gap] = min(p, q); }int main(){    cin >> n;    for(int i = 0;i < n;i ++)    {        scanf("%d%d",&a[i],&b[i]);    }    memset(dp,-1,sizeof(dp));    x = dfs(0,0);    memset(dp,-1,sizeof(dp));    cout << dfs2(0,0) << endl;    return 0;    }