#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> P;
#define REP(i,n) for(int i=0;i<int(n);i++)


int main(void){
	cin.tie(nullptr);  ios_base::sync_with_stdio(false);
	int i,j,k;

	int L,R,C;
	cin >> L >> R >> C;

	int x=1000/C;
	if(L<=x && x<=R) cout << 1000-C*x << endl;
	else if(R<x) cout << 1000-C*R << endl;
	else cout << 1000 << endl;

	return 0;
}