hd-oj-1001

Posted 2020-10-15

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