#include<bits/stdc++.h>
//#define int long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task2 "ftree"
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime cerr << (double)clock() / CLOCKS_PER_SEC * 1000 << " ms";
using namespace std;
#define getchar_unlocked getchar
inline int scan()
{
char c = getchar_unlocked();
int x = 0;
while (c < '0' || c > '9')
{
c = getchar_unlocked();
}
while (c >= '0' && c <= '9')
{
x = (x << 1) + (x << 3) + c - '0';
c = getchar_unlocked();
}
return x;
}
void phongbeo();
const int inf = 2e9;
const ll mod2 = 1e9+7;
const int mod1 = 998244353;
const ll base=67;
int add(int x,int y)
{
if(x+y>=mod2) x-=mod2;
if(x+y<0)x+=mod2;
return x+y;
}
struct icd
{
long double a;
int b;
};
struct ib
{
int a;
int b;
};
struct ic
{
int a,b,c;
};
struct id
{
int a, b, c, d;
};
struct ie
{
int a, b, c, d, e;
};
ll n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
ll i, s10, s12,k1,k2,k3,s11,lim,w,l,r ;
ll kk;
ll el = 19;
main()
{
if(fopen(task2".inp","r"))
{
fin(task2);
fou(task2);
}
if(fopen(task".inp","r"))
{
fin(task);
fou(task);
}
NHP
/// cin>>s1;
//modwwe
phongbeo(),down
// checktime
}
int a[3007][3007];
int dp[3007][3007][3];
bool check(int x,int y,int z)
{
if(z==0)
{
if(a[x][y]==0&&a[x][y+1]==1&&a[x][y+2]==2) return 1;
}
else if(a[x][y]==0&&a[x+1][y]==1&&a[x+2][y]==2) return 1;
return 0;
}
void phongbeo()
{
cin>>n>>m;
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++)
{
char s;
cin>>s;
if(s=='R')a[i][j]=0;
else if(s=='G')a[i][j]=1;
else a[i][j]=2;
}
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++)
{
for(int f=0; f<=2; f++)
{
if(check(i,j,1))dp[i][j][2]=max(dp[i][j][2],dp[i-1][j+1][f]+1);
if(f!=2)
dp[i][j][f]=max(dp[i][j][f],dp[i-1][j+1][f+1]);
}
if(check(i,j,0))
dp[i][j][0]=max(dp[i-1][j+1][0]+1,dp[i][j][0]);
dp[i][j][0]=max(dp[i][j][0],dp[i-1][j+1][0]);
if(i==n||j==1)
{
s4+=max({dp[i][j][0],dp[i][j][1],dp[i][j][2]});
}
}
cout<<s4;
}
