2
2 6 8 1 3 1
2 1 3 8 6 7
 2
1 8 9 1 1 0
2 3 4 5 6 7
 2
0 2 9 8 1 7
6 7 4 3 2 5
 3
9 4 6 2 7 0
3 7 1 9 6 4
6 1 0 8 7 2
 3
2 7 4 0 7 1
5 5 4 9 1 4
2 1 7 5 1 7
 3
5 1 2 9 6 4
9 0 6 4 2 8
4 6 2 8 3 7
 3
1 1 1 0 2 3
4 5 6 7 8 9
0 0 0 0 0 0
 1
1 9 8 3 7 8
 3
2 6 3 7 1 0
9 1 2 4 7 6
1 4 8 7 6 2
 1
4 6 9 8 2 7
 2
1 7 6 9 2 5
1 6 7 0 9 2
 3
4 1 0 8 0 2
1 5 3 5 0 7
7 7 2 7 2 2
 1
7 6 5 8 9 0
 3
3 8 3 5 5 5
3 0 1 6 6 3
0 4 3 7 2 4
 1
8 1 9 2 9 7
 2
2 0 5 7 0 8
4 5 1 5 4 9
 3
1 1 1 1 1 1
0 2 3 4 5 6
7 8 9 2 3 4
 3
0 1 1 2 2 3
4 5 6 7 8 9
3 4 5 6 7 1
 1
0 8 7 1 3 2
 2
9 3 3 6 7 2
6 2 9 1 5 9
 1
8 2 7 4 1 0
 2
3 6 8 9 5 0
6 7 0 8 2 3
 1
0 1 2 3 4 5
 3
3 4 5 6 8 9
1 1 1 1 1 1
1 2 4 5 7 0
 2
2 3 5 1 9 6
1 6 8 7 3 9
 2
0 9 5 7 6 2
8 6 2 7 1 4
 2
4 3 8 6 0 1
4 7 1 8 9 0
 1
6 2 8 4 5 1
 1
4 0 9 6 3 1
 2
6 0 1 7 2 9
1 3 4 6 7 0
 3
5 0 7 6 2 1
2 7 4 6 1 9
0 2 6 1 7 5
 3
0 1 1 2 2 3
4 5 6 7 8 9
3 4 5 6 7 8
 3
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
 2
2 4 0 3 7 6
3 2 8 7 1 5
 1
7 3 6 9 8 1
 3
1 1 2 3 4 5
6 7 8 9 0 2
3 4 5 6 7 8
 3
9 4 3 0 2 6
7 0 5 3 3 9
1 0 7 4 6 7
 1
3 7 7 6 4 2
 3
2 5 7 4 2 7
1 5 5 9 0 3
8 2 0 1 5 1
 2
1 7 8 6 0 9
3 2 1 7 4 9
 2
0 8 6 2 1 3
5 2 7 1 0 9
 2
5 3 2 9 8 2
0 7 4 8 1 8
 3
3 8 5 1 5 5
1 5 7 2 6 9
4 3 4 8 8 9
 2
5 1 2 3 0 8
3 6 7 4 9 2
 2
0 1 2 3 4 5
6 7 8 9 1 2
 1
5 3 8 0 2 6
 1
0 7 6 3 2 4
 2
8 0 6 5 1 4
7 1 0 8 3 4
 2
7 8 6 1 4 5
8 6 4 3 2 5
 2
0 1 2 3 4 5
6 6 6 7 8 9
 3
9 3 1 8 4 6
6 9 1 2 0 7
8 9 1 5 0 3
 3
0 6 2 9 5 4
3 8 0 1 6 9
6 9 0 1 5 2
 3
0 1 2 2 4 5
6 7 8 9 0 1
3 3 4 5 6 7
 1
1 4 5 7 0 5
 2
8 6 4 1 2 0
7 8 5 3 2 1
 3
5 6 2 9 3 5
5 4 1 5 9 8
4 4 2 0 3 5
 1
9 8 1 6 5 7
 3
7 2 1 3 6 9
0 3 8 4 7 6
1 4 5 8 7 0
 3
9 4 3 3 9 3
1 0 3 4 5 3
2 9 6 2 4 1
 3
1 2 3 7 8 9
9 8 7 1 2 3
7 9 2 3 1 8
 3
8 1 8 2 7 1
9 1 9 9 4 7
0 0 9 0 4 0
 1
2 5 9 6 7 9
 3
4 6 0 3 9 2
8 6 9 0 7 2
6 9 3 2 5 7
 3
8 6 0 5 4 9
1 8 5 3 9 7
7 4 5 1 6 8
 1
8 6 0 9 4 2
 1
7 9 2 5 0 4
 1
6 0 7 5 4 8
 2
5 8 4 7 1 2
0 8 6 2 4 9
 1
5 2 2 5 6 7
 2
6 5 2 7 1 3
3 7 8 1 0 9
 1
8 3 5 4 2 9
 3
0 1 2 3 4 5
6 7 8 9 1 2
3 4 5 6 7 8
 2
6 6 4 7 9 0
2 1 2 8 6 4
 3
2 3 4 5 6 7
3 4 5 6 7 8
9 1 2 3 4 5
 2
0 1 2 3 4 5
4 5 6 7 8 9
 3
2 7 3 6 4 5
0 2 1 9 4 8
8 6 9 5 4 0
 2
0 1 2 3 4 5
6 7 8 9 6 6
 2
1 7 2 0 4 3
5 2 3 6 1 0
 1
6 2 8 5 1 3
 3
5 4 8 1 6 7
0 9 3 5 8 6
2 4 7 8 1 3
 1
6 3 1 9 4 9
 3
0 1 9 1 0 8
9 9 3 5 6 2
9 3 9 9 7 3
 3
8 1 6 8 6 8
7 0 2 5 8 4
5 2 0 3 1 9
 3
2 0 1 3 4 5
6 7 8 9 1 1
3 4 5 6 6 7
 3
4 4 5 0 6 6
7 1 6 9 5 4
5 0 4 0 3 9
 2
0 1 2 3 4 5
9 8 7 6 5 4
 2
0 2 9 1 8 5
0 7 4 3 2 5
 2
2 3 9 1 6 7
2 5 4 3 0 6
 2
5 7 4 2 1 9
2 2 7 1 1 8
 1
3 9 1 7 4 5
 3
7 7 2 5 3 2
3 0 0 6 4 4
1 2 1 1 9 1
 1
7 9 5 0 4 6
 3
7 1 3 0 2 4
2 4 3 0 9 5
1 9 8 0 6 5
 1
4 3 8 9 2 3

3
 9
 9
 4
 2
 10
 10
 1
 4
 0
 2
 5
 0
 8
 2
 2
 10
 19
 3
 3
 2
 0
 5
 19
 3
 2
 1
 2
 1
 4
 2
 9
 5
 8
 1
 10
 7
 0
 5
 4
 3
 5
 9
 9
 29
 0
 0
 1
 8
 9
 21
 6
 21
 1
 8
 6
 1
 21
 6
 3
 2
 0
 0
 1
 0
 0
 0
 2
 0
 3
 0
 98
 2
 9
 9
 10
 9
 7
 3
 21
 1
 3
 32
 19
 1
 9
 5
 7
 2
 1
 7
 0
 65
 0

/*-------property of the half blood prince-----*/

#include <bits/stdc++.h>
#include <dirent.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#define MIN(X,Y) X<Y?X:Y
#define MAX(X,Y) X>Y?X:Y
#define ISNUM(a) ('0'<=(a) && (a)<='9')
#define ISCAP(a) ('A'<=(a) && (a)<='Z')
#define ISSML(a) ('a'<=(a) && (a)<='z')
#define ISALP(a) (ISCAP(a) || ISSML(a))
#define MXX 10000000000
#define MNN -MXX
#define ISVALID(X,Y,N,M) ((X)>=1 && (X)<=(N) && (Y)>=1 && (Y)<=(M))
#define LLI long long int
#define VI vector<int>
#define VLLI vector<long long int>
#define MII map<int,int>
#define SI set<int>
#define PB push_back
#define MSI map<string,int>
#define PII pair<int,int>
#define PLLI pair<LLI,LLI>
#define PDD pair<double,double>
#define FREP(i,I,N) for(int (i)=(int)(I);(i)<=(int)(N);(i)++)
#define eps 0.0000000001
#define RFREP(i,N,I) for(int (i)=(int)(N);(i)>=(int)(I);(i)--)
#define SORTV(VEC) sort(VEC.begin(),VEC.end())
#define SORTVCMP(VEC,cmp) sort(VEC.begin(),VEC.end(),cmp)
#define REVV(VEC) reverse(VEC.begin(),VEC.end())
#define INRANGED(val,l,r) (((l)<(val) || fabs((val)-(l))<eps) && ((val)<(r) || fabs((val)-(r))<eps))
#define INRANGEI(val,l,r) ((val)>=(l) && (val)<=(r))
#define MSET(a,b) memset(a,b,sizeof(a))
using namespace std;
using namespace __gnu_pbds;

//int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction
//int dx[]={1,1,0,-1,-1,-1,0,1};int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction
//int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction
//int dx[]={2,1,-1,-2,-1,1};int dy[]={0,1,1,0,-1,-1}; //Hexagonal Direction


//typedef tree < int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update > ordered_set;

int cubes[4][10];

int highestonedigit(int n){
    int has[10];
    MSET(has,0);
    FREP(i,1,n){
        FREP(j,1,6){
            has[cubes[i][j]]  = 1;
        }
    }
    FREP(i,1,9){
        if(!has[i])return i;
    }
    return -1;
}

bool can2(int dig, int n){
    cout<<"cheking "<<dig<<"\n";
    int need1 = dig%10;
    int need2 = dig/10;
    vector<int>has1;
    vector<int>has2;
    FREP(i,1,n){
        FREP(j,1,6){
            if(cubes[i][j]==need1){
                has1.PB(i);
            }
            if(cubes[i][j]==need2){
                has2.PB(i);
            }
        }
    }
    //FREP(i,0,has1.size()-1){cout<<has1[i]<<" ";}
    //cout<<"\n";
    //FREP(i,0,has2.size()-1){cout<<has2[i]<<" ";}
    //cout<<"\n";
    FREP(i,0,has1.size()-1){
        FREP(j,0,has2.size()-1){
            int one = has1[i];
            int two = has2[j];
            if((one!=two)){
                return true;
            }
        }
    }
    return false;
}

int highesttwodigit(int n){
    FREP(i,10,99){
        if(!can2(i,n))return i;
    }
    return -1;
}

bool can3(int dig, int n){
    int need1 = dig%10;
    int need2 = (dig/10)%10;
    int need3 = dig/100;
    vector<int>has1;
    vector<int>has2;
    vector<int>has3;
    FREP(i,1,n){
        FREP(j,1,6){
            if(cubes[i][j]==need1){
                has1.PB(i);
            }
            if(cubes[i][j]==need2){
                has2.PB(i);
            }
            if(cubes[i][j]==need3){
                has3.PB(i);
            }
        }
    }
    FREP(i,0,has1.size()-1){
        FREP(j,0,has2.size()-1){
            FREP(k,0,has3.size()-1){
                int one = has1[i];
                int two = has2[j];
                int three = has3[k];
                if((one!=two) && (two!=three) && (three!=one)){
                    return true;
                }
            }
        }
    }
    return false;
}

int highestthreedigit(int n){
    FREP(i,100,999){
        if(!can3(i,n))return i;
    }
    return -1;
}

int main(){

    int n;
    scanf("%d",&n);
    FREP(i,1,n){
        FREP(j,1,6){
            scanf("%d",&cubes[i][j]);
        }
    }
    int one = highestonedigit(n);
    if(one!=-1){
        printf("%d\n",one-1);
    }
    else{
        int two = highesttwodigit(n);
        if(two!=-1){
            printf("%d\n",two-1);
        }
        else{
            int three = highestthreedigit(n);
            if(three!=-1){
                printf("%d\n",three-1);
            }
            else{
                printf("999\n");
            }
        }
    }
    return 0;

}
