```
#include<bits/stdc++.h>
using namespace std;
int d[20000001],n;
double a,b;
int main()
{
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>a>>b;
for(double j=1;j<=b;j++)
{
if( d [ int (j * a) ] == 0) d [ int (j * a) ] = 1;
else d [ int (j * a) ] = 0;
}
}
for(int i=1; ;i++)
{
if(d[i]==1)
{
cout<<i;
break;
}
}
return 0;
}
```
by lunxiaotong0118 @ 2024-02-18 09:39:54
也参考下我的
```cpp
#include<bits/stdc++.h>
using namespace std;
int a[2000003];
double s,t;
int jtrdrqe6;
int main()
{
int n;
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>s>>t;
for(double j=1;j<=t;++j)
a[int(s*j)]++;
}
for(int i=1;;i++)
if(a[i]%2==1)
{
cout<<i;
break;
}
return 0;
}
```
by laoliubazicode @ 2024-02-20 17:00:00