#include "bits/stdc++.h"
using namespace std;

#define ll long long int 
#define pb(a) push_back(a)
#define vll vector<ll>
#define loop(i, n) for(ll i=1;i<=n;i++)
#define loop0(i, n) for(ll i=0;i<n;i++)
#define in(i) scanf("%lld", &i);
#define out(i) printf("%lld", i)
#define pll pair<ll, ll>
#define vpll vector<pair<ll, ll>>
#define mp(i, j) make_pair(i, j);
const ll mod = 1000000007;
const ll big = 2999999999999999999;
const ll small = -2999999999999999999;
void in2(ll& a, ll& b) { in(a); in(b); }
void in3(ll& a, ll& b, ll& c) { in(a); in(b); in(c); }
void swap(ll& a, ll& b) { a = a+b; b = a-b; a = a-b; }
void arrayIn(vll& a, ll& n) { loop0(i, n) in(a[i]); }

ll n, m, a, b, c, u, v, p, q, k;


int main()
{
  ll t;
  t = 1;
  while(t--)
  {
    in3(a, b, c);
    cout<<21-a-b-c<<"\n";
  }
}


#include<bits/stdc++.h>
using namespace std;
# define ll long long
# define read read1<ll>()
# define Type template<typename T>
Type T read1(){
	T t=0;
	char k;
	bool vis=0;
	do (k=getchar())=='-'&&(vis=1);while('0'>k||k>'9');
	while('0'<=k&&k<='9')t=(t<<3)+(t<<1)+(k^'0'),k=getchar();
	return vis?-t:t;
}
# define fre(k) freopen(k".in","r",stdin);freopen(k".out","w",stdout)
int main(){
	int x=-1;
	for(int T=read;T--;){
		int a=read,b=read,c=read;
		if(c>a&&(b<x||!~x))x=b;
	}cout<<x;
	return 0;
}
