solve.js

const sum = (arr, start, count) => arr.slice(start, start + count).reduce((res, val) => res + val, 0);

const solve = (n, a, b, c) => {
    let i = 0;
    let res = 0;
    while(i < n) {
        if (sum(a, i, 2) && b[i] + a[i + 1] > c[i]) {
            res += c[i];
            i += 3;
        } else if (sum(a, i, 1) > b[i]) {
            res += b[i];
            i += 2;
        } else {
            res += a[i];
            i++;
        }
    }
    return res;
};

console.log(`${solve(
    5,
    [5, 2, 5, 20, 20],
    [10, 10, 5, 20, 1],
    [15, 15, 5, 1, 1]
)}`);