#include <bits/stdc++.h>
#define ll long long
#define pll pair<ll,ll>
#define fi first
#define se second
using namespace std;
const ll mod=1e9+7;
const ll inf=1e17;
const ll N=2e3+3;
const ll dx[4]={-1,0,1,0}; /// ^ > v <
const ll dy[4]={0,1,0,-1};
const char dc[4]={'^','>','v','<'};
struct dd {
ll i,j;
char cc;
};
dd trace[N][N];
ll n,m,cnt=0;
char a[N][N],c[N][N];
bool vis[N][N];
ll si=0,sj=0,ei=0,ej=0;
ll change[N][N];
bool dk(ll i,ll j,ll n,ll m) {
return (i>=1 && i<=n && j >=1 && j<=m);
}
void bfs(ll sii,ll sjj,ll eii,ll ejj) {
for (ll i=1;i<=n;i++) {
for (ll j=1;j<=m;j++) change[i][j]=inf;
}
change[sii][sjj]=0;
deque <pll> q;
q.push_front({sii,sjj});
while (!q.empty()) {
pll fr=q.front();
q.pop_front();
ll ff=fr.fi,ss=fr.se;
if (vis[ff][ss]) continue;
vis[ff][ss]=true;
for (ll i=0;i<4;i++) {
ll tmp=0;
ll fff=ff+dx[i];
ll sss=ss+dy[i];
if (dk(fff,sss,n,m)) {
/// cout<<fff<<' '<<sss<<endl;
ll tmp=0;
if (a[ff][ss] != dc[i]) tmp=1;
if (a[fff][sss]=='o') tmp=0;
if (change[fff][sss] > change[ff][ss]+tmp) {
change[fff][sss]=change[ff][ss]+tmp;
trace[fff][sss]={ff,ss,dc[i]};
if (!tmp) q.push_front({fff,sss});
else q.push_back({fff,sss});
}
}
}
}
return ;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
if (fopen("p1.inp","r")) {
freopen("p1.inp","r",stdin);
freopen("p1.out","w",stdout);
}
cin>>n>>m;
for (ll i=1;i<=n;i++) {
for (ll j=1;j<=m;j++) {
cin>>a[i][j];
c[i][j]=a[i][j];
if (a[i][j]=='o') {
si=i,sj=j;
}
if (a[i][j]=='x') {
ei=i,ej=j;
}
}
}
ll c1=ei,c2=ej;
// cout<<si<<' '<<sj<<' '<<ei<<' '<<ej<<endl;
/** for (ll i=1;i<=n;i++) {
for (ll j=1;j<=m;j++) {
cout<<a[i][j];
}
cout<<endl;
} */
bfs(si,sj,ei,ej);
// cout<<1<<endl;
// ll ff=ei,ss=ej;
/// cout<<ei<<' '<<ej<<endl;
while (trace[ei][ej].i != si || trace[ei][ej].j != sj) {
ll ff=ei,ss=ej;
ei=trace[ff][ss].i;
ej=trace[ff][ss].j;
c[ei][ej]=trace[ff][ss].cc;
// cout<<1<<endl;
// cout<<ei<<' '<<ej<<endl;
// ll ff=ei,ss=ej;
}
for (ll i=1;i<=n;i++) {
for (ll j=1;j<=m;j++) {
if (a[i][j] != c[i][j]) {
/// cout<<1<<endl;
cnt++;
}
}
}
// cout<<c1<<' '<<c2<<endl;
cout<<cnt<<endl;
/// cout<<change[c1][c2]<<endl;
// cout<<n<<' '<<m<<endl;
for (ll i=1;i<=n;i++) {
for (ll j=1;j<=m;j++) {
cout<<c[i][j];
}
cout<<endl;
}
/// cout<<111111<<endl;
return 0;
}
