Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		_, M := io.NextInt(), io.NextInt()
		if M == 0 {
			break
		}
		r := io.NextInt()
		t, m, s := make([]int, r), make([]int, r), make([]int, r)
		for i := 0; i < r; i++ {
			t[i], _, m[i], s[i] = io.NextInt(), io.NextInt(), io.NextInt()-1, io.NextInt()
		}
		q := io.NextInt()
		for i := 0; i < q; i++ {
			ss, ee, mm := io.NextInt(), io.NextInt(), io.NextInt()-1
			x := make([]int, 1300)
			for j := 0; j < r; j++ {
				if m[j] == mm {
					if s[j] == 1 {
						x[t[j]]++
					} else {
						x[t[j]]--
					}
				}
			}
			for j := 1; j < 1300; j++ {
				x[j] = x[j] + x[j-1]
			}
			ans := 0
			for j := ss; j < ee; j++ {
				if x[j] > 0 {
					ans++
				}
			}
			io.Println(ans)
		}
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include<bits/stdc++.h>
using namespace std;

#define MAX 1100
#define TS 780
#define TE 870


int main(){

  while(1){
    int N,M, r, q, time[MAX][2000] = {};
    int t, n, m, s, ts, te;
    cin>>N>>M;
    if(!N&&!M)break;
    cin>>r;
    for(int i = 1; i <= r; i++){
      cin>>t>>n>>m>>s;
      if(!s){
	time[n][t+1] -= m;
      }else {
	time[n][t] += m;
      }
    }

    for(int j = 540; j <= 1260; j++){
      for(int k = 1; k <= N; k++){//cout<<time[k][j]<<" ";cout<<endl;
	time[k][j] += time[k][j-1];
      }
    }
    /* for(int j = TS; j <= TE; j++){cout<<j<<" ";
      for(int k = 1; k <= N; k++)cout<<time[k][j]<<" ";cout<<endl;
      }*/
 
    cin>>q;
    for(int i = 1; i <= q; i++){
      int ans = 0, temp = 0, f = 0, k = 1;
      cin>>ts>>te>>m;
      for(int j = ts; j <= te;j++){//cout<<"----"<<j<<" "<<k<<endl;
	for(k = 1; k <= N; k++){
		
	  if(time[k][j] == m){//cout<<k<<" "<<j<<" "<<m<<endl;
		int l = j;
	    while(time[k][l+1] && l + 1 <= te)l++;
	    ans += l-j;// cout<<ans<<" =ans  "<<l<<" "<<j<<endl;
	    //if(m == time[k][j-1] && j-1 >= ts)ans++;
	    //if(l != f)f = 0;
	    j = l;
	    for(int x = 1; x <= N; x++){//cout<<time[x][j]<<" "<<j<<endl;
	      if(m == time[x][j] && j >= ts && te > j && m == time[x][j+1]){k = x-1;j++;ans++;/*cout<<time[x][j]<<"a"<<endl;break;*/ }
	    }
	  }
	}
      }
      cout<<ans<<endl;
    }
  }

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#define rep(i,a,b) for(int i=(a); i<(b); i++)

using namespace std;
int N , M;

typedef struct data {
  int time, pc, user, on;
} data;

int main(){
  while(cin >> N >> M , N + M){
    data input[1000];
    int r; cin >> r;
    rep(i,0,r){
      int time , pc , user , on;
      cin >> input[i].time >> input[i].pc >> input[i].user >> input[i].on;
    }
    int q; cin >> q;
    rep(i,0,q){
      int ans = 0, on = 0;
      int start_pc;
      int ts, te, user; cin >> ts >> te >> user;
      rep(j,0,r){
        if(input[j].user != user) continue;
        if(input[j].on){
          if(on == 0) start_pc = input[j].pc;
          on++;
        }
        else on--;
        if(!on){
          int k = j - 1;
          while(!(input[k].pc == start_pc && input[k].on)) k--;
          if(te - max(input[k].time , ts) > 0)
            ans += te - max(input[k].time , ts);
          else{
            int start = max(input[k].time , ts);
            int end = min(input[j].time , te);
            if(end - start >= 0){
              cout
                << "  " << start
                << " " << end
                << endl;
              ans += end - start;
            }
          }
          if(input[j].time > te){
            int k = j - 1;
            while(!(input[k].pc == start_pc && input[k].on)) k--;
          }
        }
      }
      cout << ans << endl;
    }
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

const int MAX_M=10010,MAX_T=1300;

int N,M,r,q,t,n,m,s,ts,te;
vector<vector<int>> record(MAX_M,vector<int>(MAX_T));


int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
	while(cin >> N >> M,N){
		for (int i=0;i<M;++i){
			fill(record[i].begin(),record[i].end(),0);
		}
		cin >> r;
		for (;r--;){
			cin >> t >> n >> m >> s; --m;
			if (s) ++record[m][t];
			else --record[m][t];
		}
		for (int i=0;i<M;++i){
			for (int j=0;j<MAX_T-1;++j) record[i][j+1]+=record[i][j];
			for (int j=0;j<MAX_T;++j) record[i][j]=min(1,record[i][j]);
			for (int j=0;j<MAX_T-1;++j) record[i][j+1]+=record[i][j];
		}
		cin >> q;
		for (;q--;){
			cin >> ts >> te >> m; --m;
			cout << record[m][--te]-record[m][--ts] << '\n';
		}
	}
}

C++: //#include <bits/stdc++.h>
#include<iostream>
#include<stdio.h>
#include<bitset>
#include<algorithm>
#include<vector>
#include<list>
#include<queue>
#include<stack>
#include<string>
#include<math.h>
#include<string.h>

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;


int main(void) {

	while (1) {
		int N, M, r, q;
		int t, n, m, s;
		int ts, te;

		cin >> N >> M;
		vector <vector <int> > dp(M + 1, vector<int>(723, 0));

		cin >> r;
		FOR(i, 1, r) {
			cin >> t >> n >> m >> s;
			if (s == 0) {
				dp[m][t - 538]--;
			}
			else {
				dp[m][t - 539]++;
			}
		}
		FOR(i, 1, M) {
			FOR(j, 1, 722) {
				dp[i][j] += dp[i][j - 1];
			}
		}
		/*cout << endl;
		FOR(i, 1, 722) {
			cout << i+539 << " " << dp[1][i] << endl;
		}*/
		cin >> q;
		FOR(i, 1, q) {
			int total = 0;
			int first = -1, end = -1;
			cin >> ts >> te >> m;
			FOR(j, ts - 539, te - 539) {
				if (first == -1 && dp[m][j] >= 1) {
					first = j;
				}
				if (first != -1 && dp[m][j] <= 0) {

					end = j;
					//cout << "a" << first + 539 << " " << end + 539 << endl;
					total += end - first - 1;
					first = -1;
					end = -1;
				}
				if (j == te - 539 && first != -1) {
					//cout << "b" << first + 539 << " " << j + 539 << endl;
					total += j - first;
				}
			}
			cout << total << endl;
		}
	}

	return 0;
}