hdu 1001

Sum Problem

[b]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

1
100

Sample Output

1

5050

#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;
}

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