1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
#include<bits/stdc++.h>
#include<chrono>
#define ff first
#define ss second
#define eb emplace_back
#define putchar putchar_unlocked
#define getchar getchar_unlocked
#define debug if(0)
using namespace std;
typedef long long int LL;
typedef long double LD;
typedef short int SH;

inline void readI(int *i)
{
	register int r=0;
	register char c=getchar();
	int z=1;
	if(c == '-')
	{
		z=-1;
	}
	while(c < '0' || c > '9')
	{
		c=getchar();
		if(c == '-')
		{
			z=-1;
		}
	}
	while(c >= '0' && c <= '9')
	{
		r=(r<<3)+(r<<1)+c-'0';
		c=getchar();
	}
	*i=(r*z);
}
inline void readUI(int *i)
{
	register int r=0;
	register char c=getchar();
	while(c < '0' || c > '9')
	{
		c=getchar();
	}
	while(c >= '0' && c <= '9')
	{
		r=(r<<3)+(r<<1)+c-'0';
		c=getchar();
	}
	*i=r;
}
inline void readLL(LL *l)
{
	register LL r=0;
	register char c=getchar();
	int z=1;
	if(c == '-')
	{
		z=-1;
	}
	while(c < '0' || c > '9')
	{
		c=getchar();
		if(c == '-')
		{
			z=-1;
		}
	}
	while(c >= '0' && c <= '9')
	{
		r=(r<<3)+(r<<1)+c-'0';
		c=getchar();
	}
	*l=(r*z);
}
inline void readULL(LL *l)
{
	register LL r=0;
	register char c=getchar();
	while(c < '0' || c > '9')
	{
		c=getchar();
	}
	while(c >= '0' && c <= '9')
	{
		r=(r<<3)+(r<<1)+c-'0';
		c=getchar();
	}
	*l=r;
}
inline void write(LL l)
{
	if(!l)
	{
		putchar(48);
	}
	else
	{
		if(l < 0)
		{
			l^=-1;
			++l;
			putchar(45);
		}
		int p=0,h[21];
		while(l)
		{
			++p;
			h[p]=(l%10)+48;
			l/=10;
		}
		for(int i=p+1; --i;)
		{
			putchar(h[i]);
		}
	}
}
inline void writeS(string s)
{
	int l=s.length();
	for(int i=0; i^l; ++i)
	{
		putchar(s[i]);
	}
}

int n,w,a,b,c,tab[2000007][2];
int main()
{
	readUI(&n);
	for(int i=0; i^n; ++i)
	{
		readUI(&a);
		readUI(&b);
		readUI(&c);
		b-=c;
		b+=1000000;
		++tab[b][a-1];
	}
	for(int i=0; i^2000001; ++i)
	{
		w+=min(tab[i][0], tab[i][1]);
	}
	write(w);
	return 0;
}