#include<bits/stdc++.h>
using namespace std;
#define task "a"
#define se second
#define fi first
#define ll long long
#define ii pair<ll, ll>
const long mxN = 3e3 + 7;
int nRow, nCol, dp[mxN][4];
string s[mxN];
int d1[2] = {1, 0};
int d2[2] = {0, 1};
char chr[4] = {'R', 'G', 'W'};
bool Check(int u, int v, bool tt)
{
if (u < 0 || v < 0)
return 0;
for (int i = 0; i < 3; i++)
{
if (u > nRow || v > nCol)
return 0;
if (s[u][v] != chr[i])
return 0;
u += d1[tt];
v += d2[tt];
}
return 1;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen(task".INP", "r", stdin);
//freopen(task".OUT", "w", stdout);
cin >> nRow >> nCol;
for (int i = 1; i <= nRow; i++)
{
cin >> s[i];
s[i] = ' ' + s[i];
}
int ans = 0;
for (int i = 2; i <= nCol + nRow; i++)
{
for (int j = min(nCol, i - 1); j > 0; j--)
{
for (int u = 2; u >= 0; u--)
dp[j][u] = 0;
for (int u = 2; u >= 0; u--)
dp[j][max(0, u - 1)] = max(dp[j][max(0, u - 1)], dp[j + 1][u]);
if (Check(i - j, j, 0))
dp[j][2] = max(dp[j][0], dp[j][1]) + 1;
if (Check(i - j, j, 1))
dp[j][0]++;
}
ans += max({dp[1][0], dp[1][1], dp[1][2]});
}
cout << ans;
}
