#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define F first
#define S second
#define pii pair<int,int>
#define piii pair<pair<int,int>,int>
const int N = 1e6+10;
const int M = 200;
const LL INF = 1e9;
const LL LINF = 2e18;
const LL MOD = 1e9+7;
const double PI = 3.141592653589793;
pair<LL,LL>p[N];
vector<pair<LL,LL>>vec;
LL gcd(LL a,LL b){return !b?a:gcd(b,a%b);}
int main(){
//freopen("out.txt","w",stdout);
LL n,a,b,Len;
scanf("%lld%lld%lld",&n,&a,&b);
// for(int i=0;i<=n;i++)
// printf("%d %d\n",(i+i/b)%a,i%b);
LL g = gcd(a,b+1);
a /= g;
if(log(a)+log(b+1)>=log(LLONG_MAX))
Len = LINF;
else
Len = a*(b+1)-a;
bool q = 0;
set<LL>st;
LL ans = 0;
for(int i=1;i<=n;i++){
scanf("%lld%lld",&p[i].F,&p[i].S);
q |= p[i].S-p[i].F+1>=Len;
p[i].F %= Len;p[i].S %= Len;
if(p[i].S>=p[i].F)
vec.push_back({p[i].F,p[i].S});
else
vec.push_back({p[i].F,Len-1}),vec.push_back({0,p[i].S});
}
sort(vec.begin(),vec.end());
LL l = 0,r = -1,ans = 0;
vec.push_back({LINF,LINF});
for(int i=0;i<vec.size();i++){
if(vec[i].F>r)
ans += r-l+1,l = vec[i].F,r = vec[i].S;
else
r = vec[i].S;
}
printf("%lld\n",q?Len:st.size());
}
Compilation message
strange_device.cpp: In function 'int main()':
strange_device.cpp:58:21: error: redeclaration of 'long long int ans'
58 | LL l = 0,r = -1,ans = 0;
| ^~~
strange_device.cpp:42:8: note: 'long long int ans' previously declared here
42 | LL ans = 0;
| ^~~
strange_device.cpp:61:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
61 | for(int i=0;i<vec.size();i++){
| ~^~~~~~~~~~~
strange_device.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | scanf("%lld%lld%lld",&n,&a,&b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
strange_device.cpp:45:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
45 | scanf("%lld%lld",&p[i].F,&p[i].S);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
