#include <iostream>
#include <fstream>
#include <sstream>
#include <string>

#include <vector>

using namespace std;
// checks if it is prime
bool Prime(int num){
    bool flag=true;

	if (num == 1) {
		return false;
	}

    for(int i = 2; i <= num / 2; i++) {
       if(num % i == 0) {
          flag = false;
          break;
       }
    }

    return flag;
}



int main() {
	ifstream input;
	string filename;
	cout << "Enter filename: ";
	cin >> filename;
	input.open(filename);

	vector<vector<int>> triang;
	string line;
	string num;
	//reading the file and stores in vector
	while(getline(input, line)) {
		istringstream nums(line);
		vector<int> tmp;
		while(nums >> num) {
			tmp.push_back(stoi(num));
		}
		triang.push_back(tmp);
	}

	/*for (int i = 0; i < triang.size(); i++) {
		for (int j = 0; j < triang[i].size(); j++) {
			cout << triang[i][j] << " ";
		}
		cout << endl;
	}*/

// with DP, starts to read triangle from bottom and goes to top.
	for (int i = triang.size()-2; i >= 0; i--) {
		

		for (int j = 0; j <= i; j++) {
			// for the bottom layer, just takes primes, compares each node's left and right child and sums
			if (i == triang.size()-2 && !Prime(triang[i][j])) {
				if (triang[i+1][j] >= triang[i+1][j+1] && !Prime(triang[i+1][j])) {
					triang[i][j] += triang[i+1][j];
				}
				else if(!Prime(triang[i+1][j+1])) {
					triang[i][j] += triang[i+1][j+1];
				}
				else {
					triang[i][j] = 0;
				}
			}
            // this is for other than bottom layer, I did not check primeness of children 
            //because I already did in the bottom layer and now I am just adding
			else if (!Prime(triang[i][j])) {
				if (triang[i+1][j] >= triang[i+1][j+1]) {
					triang[i][j] += triang[i+1][j];
				}
				else {
					triang[i][j] += triang[i+1][j+1];
				}
			}
			else {
				triang[i][j] = 0;
			}
		}
	}
	// first element is the sum of maxPath
	cout << triang[0][0] << endl;

	return 0;

}