Problem:
Score : 200 points

Problem Statement

Snuke has come to a store that sells boxes containing balls. The store sells the following three kinds of boxes:

Red boxes, each containing R red balls

Green boxes, each containing G green balls

Blue boxes, each containing B blue balls

Snuke wants to get a total of exactly N balls by buying r red boxes, g green boxes and b blue boxes.
How many triples of non-negative integers (r,g,b) achieve this?

Constraints

All values in input are integers.

1 \leq R,G,B,N \leq 3000

Input

Input is given from Standard Input in the following format:

R G B N

Output

Print the answer.

Sample Input 1

1 2 3 4

Sample Output 1

4

Four triples achieve the objective, as follows:

(4,0,0)

(2,1,0)

(1,0,1)

(0,2,0)

Sample Input 2

13 1 4 3000

Sample Output 2

87058

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;

#define PI 3.1415926535897932

//typedef long long ll;


int lcm(int a,int b) { return a*b/__gcd(a,b); }
//ll lcm(ll a,ll b) { return a*b/__gcd(a,b); }

/**
 * sort(ar.begin(),ar.end())
 * int sum=accumulate(ar.begin(),ar.end(),0);
 **/


int main(){
    int r,g,b,n,ans=0;
    scanf("%d %d %d %d",&r,&g,&b,&n);
    for (int i=0;i<n+1;i++) {
        for (int j=0;j<n+1;j++) {
            if ((i*r+j*g)>n) break;
            if ((n-(i*r+j*g))%b==0) ans+=1;
        }
    }
    printf("%d\n",ans);
    return 0;
}