// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):x)
#define uint unsigned int
#define dbl long double
using namespace std;
// mylittledoge

int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	int N, m =0, w =0, d =0;
	cin >> N;
	for(int i =0; i < N; i++) {
		int M,W,S;
		cin >> M >> W >> S;
		int x =min(S,M);
		m +=x;
		S -=x;
		M -=x;
		int y =min(S,W);
		W -=y; S -=y;
		w +=y;
		d +=min(x,W);}
	if(w >= m) {cout << m << "\n"; return 0;}
	int x =(m-w)/2;
	while(2*x > m-w) x--;
	while(2*x+2 <= m-w) x++;
	x =min(x,d);
	cout << min(m-x,w+x) << "\n";
	return 0;}

// look at my code
// my code is amazing