import os
import sys
from io import BytesIO, IOBase
def main():
pass
# region fastio
BUFSIZE = 8192
class FastIO(IOBase):
newlines = 0
def __init__(self, file):
self._fd = file.fileno()
self.buffer = BytesIO()
self.writable = "x" in file.mode or "r" not in file.mode
self.write = self.buffer.write if self.writable else None
def read(self):
while True:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
if not b:
break
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines = 0
return self.buffer.read()
def readline(self):
while self.newlines == 0:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
self.newlines = b.count(b"\n") + (not b)
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines -= 1
return self.buffer.readline()
def flush(self):
if self.writable:
os.write(self._fd, self.buffer.getvalue())
self.buffer.truncate(0), self.buffer.seek(0)
class IOWrapper(IOBase):
def __init__(self, file):
self.buffer = FastIO(file)
self.flush = self.buffer.flush
self.writable = self.buffer.writable
self.write = lambda s: self.buffer.write(s.encode("ascii"))
self.read = lambda: self.buffer.read().decode("ascii")
self.readline = lambda: self.buffer.readline().decode("ascii")
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
n,q,s,t = map(int, input().split())
alts = []
def calc(x):
if x>0:
x = abs(x)
return -1*s*x
elif x<=0:
x = abs(x)
return t*x
for i in range(n+1):
alts.append(int(input()))
queries = []
for i in range(q):
queries.append(list(map(int, input().split())))
diff = []
for i in range(n):
diff.append(alts[i+1]-alts[i])
ans = 0
for i in diff:
ans += calc(i)
for i in queries:
i[0] -= 1
a=calc(diff[i[0]])
if i[1] != n:
b = calc(diff[i[1]])
diff[i[0]] += i[2]
if i[1]!=n:
diff[i[1]] -= i[2]
ans += calc(diff[i[0]])-a
if i[1] != n:
ans += calc(diff[i[1]])-b
print(ans)
