#include<iostream>
#include<string>
#include<set>
#include<map>
#include<cstring>
#include<vector>
#include<cmath>
#include<algorithm>
using namespace std;
const int N = 211;
struct State
{
int i;
int j;
int cmdpos;
State(int ti, int tj, int tcmdpos) : i(ti), j(tj), cmdpos(tcmdpos)
{
}
bool operator<(const State &t)const
{
if (i != t.i)
{
return i < t.i;
}
else if (j != t.j)
{
return j < t.j;
}
else if (cmdpos != t.cmdpos)
{
return cmdpos < t.cmdpos;
}
else
{
return false;
}
}
bool operator==(const State &t)const
{
return !((*this) < t) && !(t < (*this));
}
};
string createNextNCmd(string current, string cmd, int n)
{
string ret = current;
while ((int)ret.length() < n)
{
ret += cmd;
}
return ret.substr(0, n);
}
int main()
{
int n;
cin >> n;
string cmd;
cin >> cmd;
int ri, rj;
char M[N][N];
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < n; ++j)
{
cin >> M[i][j];
if (M[i][j] == 'R')
{
ri = i;
rj = j;
}
}
}
int res = -1;
set<State> trail_length;
bool found = false;
string newCmd = "";
State loopStartState(-1,-1,-1);
State current(ri, rj, 0);
while (true)
{
bool skipped = false;
if (found)
{
if (current == loopStartState)
{
if (newCmd.length() == 0)
{
res = 1;
break;
}
res = newCmd.length();
for (int i = 2; i <= n; ++i)
{
if (newCmd.length() % i == 0)
{
int cmplen = newCmd.length() / i;
int matched = 0;
for (int j = 0; j < (int)newCmd.length(); j += cmplen)
{
if (strncmp(newCmd.c_str(), newCmd.c_str() + j, cmplen) == 0)
{
++matched;
}
}
if (matched == i)
{
res = cmplen;
}
}
}
break;
}
}
else
{
if (trail_length.find(current) != trail_length.end())
{
loopStartState = current;
found = true;
}
else
{
trail_length.insert(current);
}
}
switch (cmd[current.cmdpos])
{
case '<':
current.j--;
if (M[current.i][current.j] == '#')
{
current.j++;
skipped = true;
}
break;
case '>':
current.j++;
if (M[current.i][current.j] == '#')
{
current.j--;
skipped = true;
}
break;
case 'v':
current.i++;
if (M[current.i][current.j] == '#')
{
current.i--;
skipped = true;
}
break;
case '^':
current.i--;
if (M[current.i][current.j] == '#')
{
current.i++;
skipped = true;
}
break;
}
if (!skipped && found)
{
newCmd += cmd[current.cmdpos];
}
++current.cmdpos;
current.cmdpos %= cmd.length();
}
if (res == 0)
{
res = 1;
}
cout << res << endl;
return 0;
}