//#include"holiday.h"
#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define REB(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (ll)v.size()
#define ALL(v) v.begin(),v.end()
using namespace std;
mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }
const int N = 2e3 + 7;
const int Mod = 1e9 + 7;///lon
const ll INF = 1e18 + 7;
const ll BASE = 137;
const int szBL = 450;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
char dir[4] = {'v', '^', '>', '<'};
struct Trace {
int i, j;
char dir;
};
int n, m;
char a[N][N];
int dp[N][N], vis[N][N];
Trace trace[N][N];
void solution () {
cin >> n >> m;
pii ST, ED;
rep (i, 1, n) {
string s; cin >> s;
rep (j, 1, m) {
a[i][j] = s[j - 1];
if (a[i][j] == 'o') ST = {i, j};
if (a[i][j] == 'x') ED = {i, j};
}
}
deque<pii> dq;
dq.push_back(ST);
memset(dp, 0x3f, sizeof dp);
dp[ST.fs][ST.se] = 0;
while (!dq.empty()) {
pii cur = dq.front();
int i = cur.fs, j = cur.se;
dq.pop_front();
if (vis[i][j]) continue;
vis[i][j] = 1;
rep (k, 0, 3) {
int ni = i + dx[k], nj = j + dy[k];
int W = (dir[k] != a[i][j] && a[i][j] != 'o');
if (ni < 1 || ni > n || nj < 1 || nj > m)
continue;
if (dp[ni][nj] > dp[i][j] + W) {
dp[ni][nj] = dp[i][j] + W;
trace[ni][nj] = {i, j, dir[k]};
if (W == 0) dq.push_front(MP(ni, nj));
else dq.push_back(MP(ni, nj));
}
}
}
cout << dp[ED.fs][ED.se] <<"\n";
pii cur = ED;
while (cur != ST) {
Trace prv = trace[cur.fs][cur.se];
if (MP(prv.i, prv.j) != ST)
a[prv.i][prv.j] = prv.dir;
cur = MP(prv.i, prv.j);
}
rep (i, 1, n) {
rep (j, 1, m) {
cout << a[i][j];
}
cout<<"\n";
}
}
#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
int main () {
// file("c");
ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
int num_Test = 1;
// cin >> num_Test;
while (num_Test--)
solution();
}
/*
no bug challenge +32
rep (i, 0, n) {
rep (j, 0, i) {
if (j == 0 || j == i) {
C[j][i] = 1;
continue;
}
C[j][i] = (C[j][i - 1] + C[j - 1][i - 1]) % Mod;
}
}
*/
