#include <fstream>
#include <queue>
#include <vector>
#define nmax 151

using namespace std;

ifstream fin("castel.in");
ofstream fout("castel.out");

int n,m,k,c[nmax][nmax],a[nmax][nmax],rez;
bool viz[nmax][nmax],ekey[nmax*nmax];

short int dx[]= {-1,1,0,0};
short int dy[]= {0,0,-1,1};

vector < pair < int, int > > coada[nmax];

void read()
{
    int i,j;
    fin>>n>>m>>k;
    for(i=1; i<=n; i++)
    {
        for(j=1; j<=m; j++)
        {
            fin>>a[i][j];
            coada[a[i][j]].push_back(make_pair(i,j));
            c[i][j]=(i-1)*m+j;
        }
    }
    fin.close();
}

bool vecin(int x, int y)
{
    if(viz[x][y]==true)
        return true;
    for(int dir=0; dir<4; dir++)
    {
        if(viz[x+dx[dir]][y+dy[dir]]==true)
            return true;
    }
    return false;
}

void lee(int x, int y, queue < int > &coadalee)
{
    if(ekey[a[x][y]])
    {
        if(!viz[x][y])
        {
            rez++;
            viz[x][y]=true;
            if(!ekey[c[x][y]] && vecin(x,y))
            {
                coadalee.push(c[x][y]);
                ekey[c[x][y]]=true;
            }

        }
    }
}


void fillk(int key)
{
    int i;
    queue < int > coadalee;
    for(i=0; i<coada[key].size(); i++)
    {
        lee(coada[key][i].first, coada[key][i].second,coadalee);
    }
    while(!coadalee.empty())
    {
        fillk(coadalee.front());
        coadalee.pop();
    }
}
void solve()
{
    ekey[k]=true;
    fillk(k);
}

int main()
{
    read();
    solve();
    fout<<rez;
    fout.close();
    return 0;
}