C++ :

#include<bits/stdc++.h>
using namespace std;
double a,sum;
int main()
{
	cin>>a;
	if(a<=1000)
	    sum=a*0.95;
	if(a>1000)
		sum=950+(a-1000)*0.9;
	printf("%.2f",sum);
	
	return 0;
}

Pascal :

var
a,s:real;
begin
read(a);
s:=1000*0.95+(a-1000)*0.9;
if a>1000 then write(s:0:2) else write(a*0.95:0:2);
end.