#include<bits/stdc++.h>
using namespace std ;
#define F first
#define S second
#define ll long long
#define f(i , n) for(int i = 0 ; i < n ; i++)
#define a(v) v.begin() , v.end()
#define v(i, n) vector<ll> i(n) ;
#define vov(i, n) vector<vector<ll>> i(n) ;
#define mp(m) map<ll , ll> m ;
const int sz = 1e6 + 9 ;
int main(){
ios_base::sync_with_stdio(false),cin.tie(nullptr);
int n , m ;
cin >> n >> m ;
vector<vector<int>> wt(n , vector<int>(m , 1)) ;
vector<vector<int>> dist(n , vector<int>(m , INT_MAX)) ;
vector<vector<pair<int , int>>> par(n , vector<pair<int ,int>>(m)) ;
vector<vector<char>> adj(n , vector<char>(m)) ;
char h ;
int oi , oj , xi , xj ;
f(i , n){
f(j , m){
cin >> h ;
adj[i][j] = h ;
switch (h)
{
case 'o' :
oi = i ;
oj = j ;
break;
case 'x' :
xi = i ;
xj = j ;
break ;
default:
break;
}
}
}
int dx[4] = {1 , -1 , 0 , 0} , dy[4] = {0 , 0 , 1 , -1} ;
char dir[4] = {'^' , 'v' , '<' , '>'} ;
dist[oi][oj] = 0 ;
deque<pair<int , int>> dq ;
dq.push_front({oi , oj}) ;
while(!dq.empty()){
int ui = dq.front().F , uj = dq.front().S ;
dq.pop_front() ;
f(i , 4){
int ui2 = ui + dx[i] ;
int uj2 = uj + dy[i] ;
if(ui2 < n && ui2 >= 0 && uj2 < m && uj2 >= 0){
int wht = 1 ;
switch (adj[ui][uj]){
case 'v' :
if(ui2 == ui + 1){
wht = 0 ;
}
break;
case '^' :
if(ui - 1 == ui2){
wht = 0 ;
}
break;
case '>' :
if(uj + 1 == uj2){
wht = 0 ;
}
break;
case '<' :
if(uj - 1 == uj2){
wht = 0 ;
}
break;
case 'o' :
wht = 0 ;
break;
default:
break;
}
if(dist[ui][uj] + wht < dist[ui2][uj2]){
dist[ui2][uj2] = dist[ui][uj] + wht ;
par[ui2][uj2] = {ui , uj} ;
if(wht == 0){
dq.push_front({ui2 , uj2}) ;
}
else{
dq.push_back({ui2 , uj2}) ;
}
}
}
}
}
cout << dist[xi][xj] << endl;
while(xi != oi || xj != oj){
f(i , 4){
int nxi = xi + dx[i] , nxj = xj + dy[i] ;
int pxi = par[xi][xj].F , pxj = par[xi][xj].S ;
if(nxi == pxi && nxj == pxj){
adj[pxi][pxj] = dir[i] ;
xi = nxi ; xj = nxj ;
break ;
}
}
}
adj[oi][oj] = 'o' ;
f(i , n){
f(j , m){
cout << adj[i][j] ;
}
cout << endl ;
}
return 0;
}
