#include<bits/stdc++.h>
using namespace std;
constexpr int maxn = 3e3+10;
int grid[maxn][maxn], v[maxn][maxn], h[maxn][maxn], n, m;
// 0 -> no one, 1 -> vertical, 2 -> horizontal
int dp[maxn][maxn][3], diag[2*maxn];
inline int pos(int i, int j) { return m*i+j; }
int main() {
scanf("%d %d", &n, &m);
for(int i = 0; i < n; i++) {
for(int j = 0; j < m; j++) {
char c; scanf(" %c", &c);
grid[i][j] = (c=='R'?0:c=='G'?1:2);
}
}
for(int i = 0; i < n; i++) {
for(int j = 0; j < m; j++) {
if(i && i < n-1 && grid[i][j] == 1 && grid[i-1][j] == 0 && grid[i+1][j] == 2)
v[i][j] = 1;
if(j && j < m-1 && grid[i][j] == 1 && grid[i][j-1] == 0 && grid[i][j+1] == 2)
h[i][j] = 1;
}
}
// fprintf(stderr, "i j 0 1 2\n");
for(int i = 0; i < n; i++) {
for(int j = 0; j < m; j++) {
// a gente pode colocar n-1 e m-1 pq se qualquer cara tiver nos limites
// o valor dele vai ser 0 msm
if(i>0 && j+1<m)
for(int x : {0, 1, 2})
dp[i][j][0] = max(dp[i][j][0], dp[i-1][j+1][x]);
else
dp[i][j][0] = 0;
if(v[i][j]) {
if(i>0 && j+1<m)
for(int x : {0, 1})
dp[i][j][1] = max(dp[i][j][1], dp[i-1][j+1][x]+1);
else
dp[i][j][1] = 1;
}
if(h[i][j]) {
if(i>0 && j+1<m)
for(int x : {0, 2})
dp[i][j][2] = max(dp[i][j][2], dp[i-1][j+1][x]+1);
else
dp[i][j][2] = 1;
}
// fprintf(stderr, "%d %d %d %d %d\n", i, j, dp[i][j][0], dp[i][j][1], dp[i][j][2]);
}
}
int ans = 0;
for(int i = 0; i < n; i++) {
int here = 0;
for(int x : {0, 1, 2})
here = max(here, dp[i][0][x]);
ans += here;
}
for(int j = 1; j < m; j++) {
int here = 0;
for(int x : {0, 1, 2})
here = max(here, dp[n-1][j][x]);
ans += here;
}
printf("%d\n", ans);
}
