/**
* author: BERNARD B.01
**/
#include <bits/stdc++.h>
using namespace std;
template <class T>
using rpq = priority_queue<T, vector<T>, greater<T>>;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
vector<string> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
int si, sj, ei, ej;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
if (a[i][j] == 'o') {
si = i;
sj = j;
}
if (a[i][j] == 'x') {
ei = i;
ej = j;
}
}
}
const int di[4] = {-1, 0, 1, 0};
const int dj[4] = {0, 1, 0, -1};
const string dr = "^>v<";
auto Valid = [&](int i, int j) {
return (0 <= i && i < n && 0 <= j && j < m);
};
rpq<tuple<int64_t, int, int>> s;
vector dist(n, vector<int64_t>(m, LLONG_MAX));
vector parent(n, vector<int>(m, -1));
dist[si][sj] = 0;
s.emplace(0, si, sj);
while (!s.empty()) {
auto [D, i, j] = s.top();
s.pop();
if (D != dist[i][j]) {
continue;
}
for (int k = 0; k < 4; k++) {
int ni = i + di[k];
int nj = j + dj[k];
int w = int(a[i][j] != dr[k] && a[i][j] != 'o');
if (Valid(ni, nj) && D + w < dist[ni][nj]) {
dist[ni][nj] = D + w;
parent[ni][nj] = k;
s.emplace(dist[ni][nj], ni, nj);
}
}
}
cout << dist[ei][ej] << '\n';
while (true) {
int k = parent[ei][ej];
ei -= di[k];
ej -= dj[k];
if (ei == si && ej == sj) {
break;
}
a[ei][ej] = dr[k];
}
for (int i = 0; i < n; i++) {
cout << a[i] << '\n';
}
return 0;
}
