1001

Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 64700    Accepted Submission(s): 14416

Problem Description

Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge).

In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n.

 

Input

The input will consist of a series of integers n, one integer per line.

 

Output

For each case, output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.

 

Sample Input

1
100

 

Sample Output

1

5050

 

Code:

 

#include<iostream>
using namespace std;
int main()
{
 int n,sum;
 while(cin>>n)
 {
  sum=0;
  for(int i=1;i<=n;i++)
   sum+=i;
  cout<<sum<<endl<<endl;
 }

 return 0;
}