1177: 用for计算1至n的和

Memory Limit:32 MB Time Limit:1.000 S
Judge Style:Text Compare Creator:
Submit:34 Solved:38

Description

计算1至n的和

Input

输入一个正整数n

Output

输出1至n的和

Sample Input Copy

10

Sample Output Copy

55

HINT

n<=10000

Source/Category