import std.stdio, std.array, std.string, std.conv, std.algorithm; import std.typecons, std.range, std.random, std.math, std.container; import std.numeric, std.bigint, core.bitop, core.stdc.string; void main() { auto s = readln.split.map!(to!int); auto N = s[0]; auto M = s[1]; auto K = s[2].to!long; auto A = iota(M).map!(_ => readln.split.map!(to!int).array).array; A.sort!"a[1] < b[1]"; auto st = new SegmentTree!(long, max, -(1L<<59))(N+1); foreach (i; 0..N+1) st.assign(i, 0); int idx = 0; foreach (i; 0..N) { long tmp = max(st.query(0, i), 0L); while (idx < M && A[idx][0] - 1 == i) { long v = st.query(A[idx][1], A[idx][1]); long cost = tmp + A[idx][2] - K; if (A[idx][1] == N) cost += K; st.assign(A[idx][1], max(v, cost)); idx += 1; } } st.query(0, N).writeln; } class SegmentTree(T, alias op, T e) { T[] table; int size; int offset; this(int n) { size = 1; while (size <= n) size <<= 1; size <<= 1; table = new T[](size); fill(table, e); offset = size / 2; } void assign(int pos, T val) { pos += offset; table[pos] = val; while (pos > 1) { pos /= 2; table[pos] = op(table[pos*2], table[pos*2+1]); } } void add(int pos, T val) { pos += offset; table[pos] += val; while (pos > 1) { pos /= 2; table[pos] = op(table[pos*2], table[pos*2+1]); } } T query(int l, int r) { return query(l, r, 1, 0, offset-1); } T query(int l, int r, int i, int a, int b) { if (b < l || r < a) { return e; } else if (l <= a && b <= r) { return table[i]; } else { return op(query(l, r, i*2, a, (a+b)/2), query(l, r, i*2+1, (a+b)/2+1, b)); } } }