import std;

alias GasStation = Tuple!(int, "x", int, "gas", int, "cost");

long calc(int v, int l, GasStation[] ss) {
    int n = cast(int)ss.length;

    ss ~= GasStation(l, 0, 0); // sentinel
    // dp[i 番目のガソリンスタンド][ガソリンの量]
    auto dp = new long[][](n + 1, v + 1);
    foreach (i; 0..dp.length) dp[i][] = long.max;

    if (ss[0].x > v) return -1;
    dp[0][v - ss[0].x] = 0;

    for (int i = 0; i < n; i++) {
        int d = ss[i + 1].x - ss[i].x;
        for (int j = 0; j <= v; j++) {
            if (dp[i][j] == long.max) continue;

            if (j >= d) {
                // 補給なしで進む
                dp[i + 1][j - d] = min(dp[i + 1][j - d], dp[i][j]);
            }

            // 補給して進む
            auto v2 = min(v, j + ss[i].gas);
            if (v2 >= d) {
                dp[i + 1][v2 - d] = min(dp[i + 1][v2 - d], dp[i][j] + ss[i].cost);
            }
        }
    }

    long ans = dp[n].minElement;
    return ans == long.max ? -1 : ans;
}

void main() {
    int n, v, l; scan(n, v, l);
    GasStation[] ss;
    foreach (_; 0..n) {
        int x, gas, cost; scan(x, gas, cost);
        ss ~= GasStation(x, gas, cost);
    }
    writeln(calc(v, l, ss));
}

void scan(T...)(ref T a) {
    string[] ss = readln.split;
    foreach (i, t; T) a[i] = ss[i].to!t;
}
T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;