// URL: https://yukicoder.me/problems/no/752 import std.algorithm, std.array, std.container, std.math, std.range, std.typecons, std.string; version(unittest) {} else void main() { long P; int Q; io.getV(P, Q); auto maxM = min(P, 10L^^4), maxK = P/(maxM+1); auto b = new long[](maxK+1); foreach (k; 1..maxK+1) b[k] = b[k-1] + P%k; auto c = new long[](maxM+2); c[$-1] = b[$-1]; foreach_reverse (m; 1..maxM+1) { auto u = P/(m+1)+1, v = P/m; c[m] = c[m+1] + P*(v-u+1) - m*(v*(v+1)-u*(u-1))/2; } auto calc(long x) { if (x <= maxK) { return b[x]; } else { auto m = P/x, u = P/(m+1)+1; return c[m+1] + P*(x-u+1) - m*(x*(x+1)-u*(u-1))/2; } } foreach (_; 0..Q) { long L, R; io.getV(L, R); io.put(calc(R) - calc(L-1)); } } auto io = IO!()(); import std.stdio; struct IO(alias IN = stdin, alias OUT = stdout) { import std.conv, std.format, std.meta, std.traits, core.stdc.stdlib; auto getV(T...)(ref T v) { foreach (ref w; v) get(w); } auto getA(T)(size_t n, ref T v) if (hasAssignableElements!T) { v = new T(n); foreach (ref w; v) get(w); } auto getC(T...)(size_t n, ref T v) if (allSatisfy!(hasAssignableElements, T)) { foreach (ref w; v) w = new typeof(w)(n); foreach (i; 0..n) foreach (ref w; v) get(w[i]); } auto getM(T)(size_t r, size_t c, ref T v) if (hasAssignableElements!T && hasAssignableElements!(ElementType!T)) { v = new T(r); foreach (ref w; v) getA(c, w); } template getS(E...) { auto getS(T)(size_t n, ref T v) { v = new T(n); foreach (ref w; v) foreach (e; E) mixin("get(w."~e~");"); } } const struct PutConf { bool newline = true, flush, exit; string floatFormat = "%.10f", delimiter = " "; } auto put(alias conf = "{}", T...)(T v) { mixin("const PutConf c = "~conf~"; putMain!c(v);"); } auto putB(alias conf = "{}", S, T)(bool c, S t, T f) { if (c) put(t); else put(f); } auto putRaw(T...)(T v) { OUT.write(v); OUT.writeln; } private { dchar[] buf; auto sp = (new dchar[](0)).splitter; void nextLine() { IN.readln(buf); sp = buf.splitter; } auto get(T)(ref T v) { if (sp.empty) nextLine(); v = sp.front.to!T; sp.popFront(); } auto putMain(PutConf c, T...)(T v) { foreach (i, w; v) { putOne!c(w); if (i < v.length-1) OUT.write(c.delimiter); } static if (c.newline) OUT.writeln; static if (c.flush) OUT.flush(); static if (c.exit) exit(0); } auto putOne(PutConf c, T)(T v) { static if (isInputRange!T && !isSomeString!T) putRange!c(v); else if (isFloatingPoint!T) OUT.write(format(c.floatFormat, v)); else OUT.write(v); } auto putRange(PutConf c, T)(T v) { auto w = v; while (!w.empty) { putOne!c(w.front); w.popFront(); if (!w.empty) OUT.write(c.delimiter); } } } }