#include <stdio.h>
#define N 100
#define T 2000
int max(int a, int b) { return a > b ? a : b; }
int main() {
static int xxl[N + 1], xxr[N + 1], ttl[N + 1], ttr[N + 1], aal[N + 1], aar[N + 1], dp[N + 1][N + 1][T][2];
int n, nl, nr, k, i, j, l, r, t, ans, tmp;
scanf("%d%d%d", &n, &k, &n), k--;
nl = nr = 0;
while (n--) {
int a;
scanf("%d%d%d", &i, &a, &t), i--, t--;
if (i < k)
nl++, xxl[nl] = k - i, ttl[nl] = t, aal[nl] = a;
else
nr++, xxr[nr] = i - k, ttr[nr] = t, aar[nr] = a;
}
for (i = 1, j = nl; i < j; i++, j--) {
tmp = xxl[i], xxl[i] = xxl[j], xxl[j] = tmp;
tmp = ttl[i], ttl[i] = ttl[j], ttl[j] = tmp;
tmp = aal[i], aal[i] = aal[j], aal[j] = tmp;
}
ans = 0;
for (l = 0; l <= nl; l++)
for (r = 0; r <= nr; r++)
for (t = 0; t < T; t++) {
if (l == 0 && r == 0)
dp[l][r][t][0] = dp[l][r][t][1] = t == 0 ? 0 : -1;
else {
int t_;
dp[l][r][t][0] = -1;
if (l > 0) {
if ((t_ = t - (xxl[l] - xxl[l - 1])) >= 0)
dp[l][r][t][0] = max(dp[l][r][t][0], dp[l - 1][r][t_][0]);
if ((t_ = t - (xxl[l] + xxr[r])) >= 0)
dp[l][r][t][0] = max(dp[l][r][t][0], dp[l - 1][r][t_][1]);
if (dp[l][r][t][0] != -1 && t <= ttl[l])
dp[l][r][t][0] += aal[l];
}
dp[l][r][t][1] = -1;
if (r > 0) {
if ((t_ = t - (xxr[r] - xxr[r - 1])) >= 0)
dp[l][r][t][1] = max(dp[l][r][t][1], dp[l][r - 1][t_][1]);
if ((t_ = t - (xxr[r] + xxl[l])) >= 0)
dp[l][r][t][1] = max(dp[l][r][t][1], dp[l][r - 1][t_][0]);
if (dp[l][r][t][1] != -1 && t <= ttr[r])
dp[l][r][t][1] += aar[r];
}
}
ans = max(ans, max(dp[l][r][t][0], dp[l][r][t][1]));
}
printf("%d\n", ans);
return 0;
}
