#include <iostream>
#include <fstream>
#include <numeric>

using namespace std;

int main() {
    cout << "Advent of Code 2021 - Day 1 Part 2" << endl;

    ifstream filein("input");
    string line;
    int firstSlice[3], secondSlice[3];
    
    for(int i = 0; i < 3; i++) {
        getline(filein, line);
        firstSlice[i] = stoi(line);
    }

    int count = 0;

    while (getline(filein, line)) 
    {
        for(int i = 1; i < 3; i++) {
            secondSlice[i-1] = firstSlice[i];
        }

        secondSlice[2] = stoi(line);

        if(accumulate(secondSlice,secondSlice+3, 0) > accumulate(firstSlice,firstSlice+3, 0)) {
            count++;
        }

        copy(begin(secondSlice), end(secondSlice), begin(firstSlice));
    }

    cout << count << endl;

    return 0;
}