#include <stdio.h>
int main()
{
double a,b,tsum =0,useful,money =0;
int i;
for (i=0; i<5; i++)
{
scanf ("%lf %lf",&a,&b);
useful=b-a;
if (useful<=1)
{
continue;
}
else if (useful>=5)
{
useful=5;
}
tsum+=useful-1;
}
if (tsum>=15)
{
tsum*=0.95;
}
else if (tsum<=5)
{
tsum = tsum*1.00 + tsum*0.05;
}
money=tsum*10000;
printf ("%.0lf",money);
return 0;
}