#include <bits/stdc++.h>
using namespace std;
#define FOR(i, n) for(int i = 0; i < (n); i++)
#define MEM(a, x) memset(a, x, sizeof(a))
#define ALL(a) a.begin(), a.end()
#define UNIQUE(a) a.erase(unique(ALL(a)), a.end())
typedef long long ll;
typedef pair<int, int> P;

pair<int, P> dp[55][55];
int gx, gy, n, f;

int main(int argc, char const *argv[]) {
	ios_base::sync_with_stdio(false);
	cin >> gx >> gy >> n >> f;
	FOR(i, n+1) FOR(j, n+1) dp[i][j] = {gx+gy, {0, 0}};
	for (int i = 1; i <= n; i++) {
		int dx, dy, c;
		cin >> dx >> dy >> c;
		for (int j = 0; j <= i; j++) {
			if (dp[i][j].first > dp[i-1][j].first) {
				dp[i][j] = {dp[i-1][j].first, {dp[i-1][j].second.first, dp[i-1][j].second.second}};
			}
			if (j == 0) continue;
			int px = dp[i-1][j-1].second.first, py = dp[i-1][j-1].second.second;
			int nx = px + dx, ny = py + dy;
			if (nx > gx || ny > gy) continue;
			if (dp[i][j].first > dp[i-1][j-1].first - abs(gx-px) - abs(gy-py) + c + abs(gx-nx) + abs(gy-ny)) {
				dp[i][j] = {dp[i-1][j-1].first - abs(gx-px) - abs(gy-py) + c + abs(gx-nx) + abs(gy-ny), {nx, ny}};
			}
		}
	}
	sort(dp[n], dp[n]+n+1);
	cout << dp[n][0].first << endl;
	return 0;
}