记录编号	363135	评测结果	AAAAAAAAAA
题目名称	丧心病狂的韩信大点兵	最终得分	100
用户昵称	_Itachi	是否通过	通过
代码语言	C++	运行时间	0.002 s
提交时间	2017-01-10 10:35:01	内存使用	0.29 MiB

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define LL long long
LL Rabit_mul(LL a,LL b,LL c){
	return (a*b-(LL)(a/(long double)c*b+1e-3)*c+c)%c;
}
LL a1,a2,b1,b2;
LL Rabit_gcd(LL a,LL b){return b?Rabit_gcd(b,a%b):a;}
void Rabit_gcd(LL a,LL b,LL &x,LL &y){
	if(!b){x=1,y=0;return;}
	Rabit_gcd(b,a%b,y,x),y-=x*(a/b);	
}
bool Rabit_run(){
	LL g=Rabit_gcd(a1,a2),c=b2-b1;
	if(c%g)return false;
	a1/=g,a2/=g,c/=g;
	LL k,tmp,lcm,x;Rabit_gcd(a1,a2,k,tmp);
	k=(k%a2+a2)%a2;
	k=((k*1ll*c)%a2+a2)%a2;
	lcm=a1*a2*g;
	x=Rabit_mul(k,a1*g,lcm);
	x=(x+b1)%lcm;
	a1=lcm,b1=x;
	return true;
}
int main(){
	freopen("weakhanxin.in","r",stdin);freopen("weakhanxin.out","w",stdout);
	int n;scanf("%d",&n);
	scanf("%lld%lld",&a1,&b1);
	for(int i=1;i<n;i++){
		scanf("%lld%lld",&a2,&b2);
		if(!Rabit_run()){puts("-1");return 0;}
	}
	printf("%lld\n",b1);
}