#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
#include <deque>
using namespace std;

const int direct[4][2] = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}};
const int MAXN = 60;
const int MAXM = 1e4 + 10;
const int INF = 1e9 + 10;

struct node {
	int x, y, num, step;
} A[MAXN][MAXN][4];

int r, c, minn[MAXN][MAXN][MAXM], len, ans;
char Map[MAXN][MAXN], str[MAXM];
deque<node> q;

bool legal(int x, int y) {
	if (1 <= x && x <= r && 1 <= y && y <= c) return true;
	return false;
}

void bfs() {
	minn[1][1][0] = 0;
	q.push_front((node){1, 1, 0, 0});
	while (!q.empty()) {
		node p = q.front();
		if (p.num == len) {
			ans = p.step;
			return;
		}
		q.pop_front();
		int nx = p.x, ny = p.y;
		if (Map[nx][ny] == str[p.num + 1]) {
			if (minn[nx][ny][p.num + 1] > p.step) {
				minn[nx][ny][p.num + 1] = p.step;
				q.push_front((node){nx, ny, p.num + 1, p.step});
			}
		}
		for (int i = 0; i < 4; i++) {
			if (A[p.x][p.y][i].step != -1) {
				nx = A[p.x][p.y][i].x, ny = A[p.x][p.y][i].y;
				if (Map[nx][ny] == str[p.num + 1]) {
					if (minn[nx][ny][p.num + 1] > p.step + 1) {
						minn[nx][ny][p.num + 1] = p.step + 1;
						q.push_back((node){nx, ny, p.num + 1, p.step + 1});
					}
				} 
				if (minn[nx][ny][p.num] > p.step + 1) {
					minn[nx][ny][p.num] = p.step + 1;
					q.push_back((node){nx, ny, p.num, p.step + 1});
				}
			}
		}
	}
} 

int main() {
	cin >> r >> c;
	for (int i = 1; i <= r; i++) {
		for (int j = 1; j <= c; j++)
			cin >> Map[i][j];
	}
	cin >> (str + 1);
	len = strlen(str + 1);
	str[len + 1] = '*';
	len++;
	for (int i = 1; i <= r; i++) {
		for (int j = 1; j <= c; j++) {
			for (int k = 0; k < MAXM; k++) {
				minn[i][j][k] = INF;
			}
		} 
	}
	for (int i = 1; i <= r; i++) {
		for (int j = 1; j <= c; j++) {
			for (int k = 0; k < 4; k++) {
				int nx = i + direct[k][0], ny = j + direct[k][1];
				while (legal(nx, ny) && Map[nx][ny] == Map[i][j]) {
					nx += direct[k][0];
					ny += direct[k][1];
				}
				if (legal(nx, ny)) {
					A[i][j][k] = (node){nx, ny, 0, 0};
				} else {
					A[i][j][k] = (node){0, 0, 0, -1};
				}
			}
		}
	}
	bfs();
	cout << ans + len << endl;
	return 0;
}