hdu 1001

Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 412274    Accepted Submission(s): 103727

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

1100

 

Sample Output

15050

 

#include<stdio.h>int main(){int a,sum;while(scanf("%d",&a)!=EOF){sum=0;for(int i=1;i<=a;i++)sum+=i;printf("%d\n\n",sum);}return 0;}