codevs3990：中国剩余定理2

好久没做codevs啦

 #include<cstdio>
 #include<cstdlib>
 #include<algorithm>
 #include<cstring>
 #include<vector>
 #define MAXN 100000+10
 #define ll long long
 #define pb push_back
 #define ft first
 #define sc second
 #define mp make_pair
 using namespace std;
 ll M=1LL,X;
 ll c[],m[];
 int n;
 void extgcd(ll a,ll b,ll &x,ll &y){
     if(!b){
         x=,y=;
     }
     else{
         ll xx,yy;
         extgcd(b,a%b,xx,yy);
         x=yy,y=xx-a/b*yy;
     }
 }
 ll Inv(ll x,ll p){
     //(x,p)=1
     ll a,b;
     extgcd(x,p,a,b);
     return (a%p+p)%p;
 }
 ll a,b;
 int main()
 {

     scanf("%d%lld%lld",&n,&a,&b);
     for(int i=;i<=n;i++){
         scanf("%lld%lld",&m[i],&c[i]);
         M*=m[i];
     }
     for(int i=;i<=n;i++){
         X+=c[i]*M/m[i]*Inv(M/m[i],m[i]);
     }
     X%=M;
     ll s=(a-X)/M-;
     while(X+s*M<a)s++;
     ll t=(b-X)/M+;
     while(X+t*M>b)t--;
     ll ans=t-s+;
     printf("%lld\n%lld\n",ans,(ans?X+M*s:0LL));
     return ;
 }