#include <cstdio>
#include <iostream>
#include <algorithm>
#include <complex>
#include <queue>
#include <map>
#include <string>
#include <cassert>
using namespace std;

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define rep(i,n) for (int i=0;i<(n);i++)
#define Rrep(i,n) for (int i=(n)-1;i>=0;i--)
#define pb push_back
#define ALL(a) (a).begin(),(a).end()

#define PI 3.1415926535

typedef long long ll;
typedef pair<int, int> P;

const int INF = 99999999;
const int MAX_H = 500;
const int MAX_W = 500;

int H, W;
vector<string> field;

bool inside(int x, int y) {
    return 0 <= x && x < H && 0 <= y && y < W;
}

int main() {
    /* assert code */
	cin >> H >> W;

    assert(1 <= H && H <= MAX_H);
    assert(1 <= W && W <= MAX_W);
    

	field.clear();
	field.resize(H);

	// 盤面の読み込み & スタート位置、ゴール位置の取得
	int sx = -1, sy = -1, gx = -1, gy = -1;
    int cntS = 0, cntG = 0;
	rep(i, H) {
		cin >> field[i];
        assert(field[i].size() == W);
		rep(j, W) {
			if (field[i][j] == 'S') {
				sx = i;
				sy = j;
                cntS++;
			} else if (field[i][j] == 'G') {
				gx = i;
				gy = j;
                cntG++;
			} else {
                assert(field[i][j] == '.' || field[i][j] == 'R');
            }
		}
	}

    assert(inside(sx, sy));
    assert(inside(gx, gy));
    assert(cntS == 1);
    assert(cntG == 1);

}