#include <stdio.h>

int main () {
  int n = 0;
  int m = 0;
  int l[100000] = {};
  int f = 0;
  long long b = 0LL;
  long long w = 0LL;
  
  int res = 0;
  
  long long ans = 0LL;
  
  res = scanf("%d", &n);
  res = scanf("%d", &m);
  for (int i = 0; i < n; i++) {
    res = scanf("%d", l+i);
  }
  for (int i = 0; i < m; i++) {
    res = scanf("%d", &f);
    res = scanf("%lld", &b);
    res = scanf("%lld", &w);
    ans += b;
    if (f <= l[0] && w-((long long)(l[0]-f)) > b) {
      ans += w-((long long)(l[0]-f))-b;
    } else if (f >= l[n-1] && w-((long long)(f-l[n-1])) > b) {
      ans += w-((long long)(f-l[n-1]))-b;
    } else if (f > l[0] && f < l[n-1]) {
      int idx[2] = { 0, n-1 };
      while (idx[1]-idx[0] > 1) {
        int nxt = (idx[0]+idx[1])/2;
        if (l[nxt] < f) {
          idx[0] = nxt;
        } else {
          idx[1] = nxt;
        }
      }
      if (f-l[idx[0]] < l[idx[1]]-f && w-((long long)(f-l[idx[0]])) > b) {
        ans += w-((long long)(f-l[idx[0]]))-b;
      } else if (w-((long long)(l[idx[1]]-f)) > b) {
        ans += w-((long long)(l[idx[1]]-f))-b;
      }
    }
  }
  
  printf("%lld\n", ans);
  return 0;
}