CoCalc -- Collaborative Calculation in the Cloud
SharedSage genom exempel / summa.cOpen in CoCalc
#include <stdio.h>

int main(void)
{
    int S, k;
    S = 0;
    for (k = 1; k <= 12345; k++) {
        S += k;
    }
    printf("Summa: %d\n", S);
    return 0;
}