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