// Online C compiler to run C program online
#include <stdio.h>
int calc (int a){
int sum=0;
for(int i=1; i<=a; i++){
sum=sum+i;
}
return sum;
}
int main() {5
int a,i,sum=0;
scanf("%d",&a);
int result2=calc(a);
printf("Answer: %d", result2);
return 0;
}