#pragma comment(linker, "/STACK:1024000000,1024000000")#include <cstdio>#include <string>#include <cstdlib>#include <cmath>#include <iostream>#include <cstring>#include <set>#include <queue>#include <algorithm>#include <vector>#include <map>#include <cctype>#include <cmath>#include <stack>#define print(a) printf("%d\n", (a))#define freopenr freopen("in.txt", "r", stdin)#define freopenw freopen("out.txt", "w", stdout)using namespace std;typedef long long LL;typedef pair<int, int> P;const int INF = 0x3f3f3f3f;const double inf = 0x3f3f3f3f3f3f;const LL LNF = 0x3f3f3f3f3f3f;const double PI = acos(-1.0);const double eps = 1e-8;const int maxn = 1e3 + 5;const int mod = 1e9 + 7;const int dr[] = {-1, 0, 1, 0};const int dc[] = {0, 1, 0, -1};const char *Hex[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};int n, m;const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};inline int Min(int a, int b){ return a < b ? a : b; }inline int Max(int a, int b){ return a > b ? a : b; }inline LL Min(LL a, LL b){ return a < b ? a : b; }inline LL Max(LL a, LL b){ return a > b ? a : b; }inline bool is_in(int r, int c){    return r >= 0 && r < n && c >= 0 && c < m;}struct Node{    int pos, cost, det;    bool operator < (const Node &p) const{        return pos < p.pos;    }};Node a[maxn];double sum[maxn], v;double dp[maxn][maxn][2];double cal(int i, int j, int l, int r){     double t = 1.0 * fabs(a[l].pos-a[r].pos) / v;     double ans = sum[i-1] + sum[n+1] - sum[j];     return ans * t;}int solve(){    for(int i = 0; i <= n+1; ++i)        for(int j = 0; j <= n+1; ++j)            dp[i][j][0] = dp[i][j][1] = inf;    int p = lower_bound(a+1, a+n+1, (Node){m, 0, 0}) - a;    dp[p][p][0] = dp[p][p][1] = 0.0;    for(int i = p; i > 0; --i){        for(int j = p; j <= n+1; ++j){            dp[i-1][j][0] = min(dp[i-1][j][0], dp[i][j][0]+cal(i, j, i, i-1)+a[i-1].cost);            dp[i-1][j][0] = min(dp[i-1][j][0], dp[i][j][1]+cal(i, j, j, i-1)+a[i-1].cost);            dp[i][j+1][1] = min(dp[i][j+1][1], dp[i][j][0]+cal(i, j, i, j+1)+a[j+1].cost);            dp[i][j+1][1] = min(dp[i][j+1][1], dp[i][j][1]+cal(i, j, j, j+1)+a[j+1].cost);        }    }    return min(dp[1][n+1][0], dp[1][n+1][1]);}int main(){    while(scanf("%d %lf %d", &n, &v, &m) == 3 && n+v+m){        for(int i = 1; i <= n; ++i)  scanf("%d %d %d", &a[i].pos, &a[i].cost, &a[i].det);        a[n+1].pos = m;  a[n+1].cost = a[n+1].det = 0;        sort(a+1, a+n+2);        sum[0] = 0;        for(int i = 1; i <= n+1; ++i) sum[i] = sum[i-1] + a[i].det;        int ans = solve();        printf("%d\n", ans);    }    return 0;}