#include<stdio.h>
int main()
{
    int ar1[100],ar2[100];
    int n,i,j,res;
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        scanf("%d",&ar1[i]);
        scanf("%d",&ar2[i]);
        while(sizeof(ar1)!=sizeof(ar2))
        {
            ar1[i]=ar1[i]<<1;
            ar2[i]=ar2[i]<<1;
        }
    }
    for(i=0;i<n;i++)
    {
        for(j=0;j<n;j++)
        {
            res=ar1[i]*ar2[j];
        }
    }
    printf("%d",res);
    return 0;
}