#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
 
int main() {
	int m,n;
	long long X[100][100];
	string ans;
	cin>>n>>m;
	for (int i=n-1; i>=0; i--){
		for (int j=0; j<m; j++)cin>>X[i][j];
	}
	for(int i=1;i<n;i++)X[i][0]=X[i][0]+X[i-1][0];
	for(int j=1;j<m;j++)X[0][j]=X[0][j]+X[0][j-1];
	for (int i=1; i<n; i++){
		for (int j=1; j<m; j++) X[i][j]=X[i][j]+max(X[i - 1][j], X[i][j - 1]);
	}
	int k=n-1, t=m-1;
	while (k>0 || t>0){
		if (k>0 && t>0){
			if (X[k-1][t]>X[k][t-1]){
				ans+="F";
				k--;
			}
			else{
				ans+="R";
				t--;	
			} 
		}
		else if (k==0){
			ans+="R";
			t--;
		}
		else if (t==0){
			ans+="F";
			k--;
		}
	}
	reverse(ans.begin(),ans.end());
	cout<<ans;
	return 0;
}

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NCA0CjM0IDUgNyA4CjcgOCA5IDIzCjEgMiA5MDkgNTQKMyA0IDggMA==

4 4
34 5 7 8
7 8 9 23
1 2 909 54
3 4 8 0