#include <iostream>
#include <algorithm>
#include <string.h>
#include <queue>
using namespace std;
#define itn int
pair<short, short>lastp[501][501][4];
int dp[45][501][501];
char arr[501][501];
int dx[4] = { -1,0,1,0 };
int dy[4] = { 0,1,0,-1 };
int N, M, K;
int isv(int n, int m)
{
return (n < 0) || (n >= N) || (m < 0) || (m >= M) || (arr[n][m] == 'x');
}
int ge(int n, int m)
{
int ans = m - n;
int i;
for (i = 0; i < n; i++)
ans += K - i;
return ans;
}
pair<int, int> findne(int n, int m, int c)
{
if (lastp[n][m][c].first != -1)
return lastp[n][m][c];
lastp[n][m][c] = { -2,-2 };
if (isv(n, m))
{
return lastp[n][m][c];
}
int on = n;
int om = m;
int oc = c;
if (arr[n][m] == 'A')
c--;
if (arr[n][m] == 'C')
c++;
c += 4;
c %= 4;
n += dx[c];
m += dy[c];
if (isv(n, m))
{
return lastp[on][om][oc] = { on,om };
}
return lastp[on][om][oc] = findne(n, m, c);
}
vector<pair<short, short>>co[300100];
int vis[501][501];
int main()
{
memset(lastp, -1, sizeof(lastp));
memset(dp, 1, sizeof(dp));
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> K >> M >> N;
int i, j, k, l, m;
for (i = 0; i < N; i++)
{
cin >> arr[i];
}
for (i = 0; i < N; i++)
{
for (j = 0; j < M; j++)
{
if (arr[i][j] >= '0' && arr[i][j] <= '9')
{
dp[ge(arr[i][j] - '1', arr[i][j] - '1')][i][j] = 0;
}
for (k = 0; k < 4; k++)
findne(i, j, k);
}
}
int ans = 123456789;
for (i = 0; i < K; i++)
{
int j;
for (j = 0; j < K - i; j++)
{
memset(vis, 0, sizeof(vis));
int s = j;
int e = j + i;
for (k = 0; k <= N * M; k++)
{
co[k].clear();
}
for (k = s; k < e; k++)
{
for (l = 0; l < N; l++)
{
for (m = 0; m < M; m++)
{
dp[ge(s, e)][l][m] = min((int)dp[ge(s, e)][l][m], dp[ge(s, k)][l][m] + dp[ge(k + 1, e)][l][m]);
if (i == K - 1)
ans = min(ans, (int)dp[ge(s, e)][l][m]);
}
}
}
for (l = 0; l < N; l++)
{
for (m = 0; m < M; m++)
{
if (dp[ge(s, e)][l][m] <= N * M)
co[dp[ge(s, e)][l][m]].push_back({ l,m });
}
}
for (k = 0; k <= N * M; k++)
{
int l;
for (l = 0; l < co[k].size(); l++)
{
if (co[k][l].first < 0 || vis[co[k][l].first][co[k][l].second])
continue;
dp[ge(s, e)][co[k][l].first][co[k][l].second] = k;
if (i == K - 1)
ans = min(ans, k);
vis[co[k][l].first][co[k][l].second] = 1;
for (m = 0; m < 4; m++)
{
co[k + 1].push_back(lastp[co[k][l].first][co[k][l].second][m]);
}
}
}
}
}
if (ans > N * M)
cout << -1;
else
cout << ans;
}
