#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define MAXN 2005
#define ii pair<int,int>
#define bit(i,j) ((i>>j)&1)
#define sz(i) (int)i.size()
#define endl '\n'
using namespace std;
const int INF = 1e9 + 7;
int dx[] = {0, 0, -1, 1},
dy[] = {1, -1, 0, 0};
int n, m;
char a[MAXN][MAXN], c[4] = {'>', '<', '^', 'v'};
ii st, ed;
namespace sub1
{
int dp[MAXN][MAXN];
struct trip
{
int u, v, k;
};
trip trace[MAXN][MAXN];
bool check(int i, int j)
{
return (i < 1 || j < 1 || i > n || j > m);
}
void bfs()
{
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++)
dp[i][j] = INF;
deque<ii>q;
q.push_front(st);
dp[st.F][st.S] = 0;
while(sz(q))
{
ii top = q.front();
q.pop_front();
int u = top.F, v = top.S;
for(int i = 0; i < 4; i++)
{
int nx = u + dx[i], ny = v + dy[i];
if(check(nx, ny))
continue;
int cost = (a[u][v] != 'o' && a[u][v] != c[i]);
if(dp[nx][ny] > dp[u][v] + cost)
{
dp[nx][ny] = dp[u][v] + cost;
trace[nx][ny] = {u, v, i};
if(cost)
q.push_back({nx, ny});
else
q.push_front({nx, ny});
}
}
}
}
void query()
{
queue<ii>q;
q.push(ed);
while(sz(q))
{
ii top = q.front();
q.pop();
if(a[top.F][top.S] == 'o')
break;
trip x = trace[top.F][top.S];
q.push({x.u, x.v});
if(a[x.u][x.v] != 'o')
a[x.u][x.v] = c[x.k];
}
}
void solve()
{
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++)
{
if(a[i][j] == 'o')
st = {i, j};
if(a[i][j] == 'x')
ed = {i, j};
}
bfs();
query();
cout << dp[ed.F][ed.S] << endl;
for(int i = 1; i <= n; i++)
{
for(int j = 1; j <= m; j++)
cout << a[i][j];
cout << endl;
}
}
}
main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++)
cin >> a[i][j];
sub1::solve();
}
