sum of 1-100 numbers by using for loop

#include<stdio.h>
int main()
{
    int i;
    int a=100;
    int sum=0;
    for(i=1;i<=a;i++)
    {
        printf("%d\n",i);{


        sum+=i;
        printf("sum=%d upto first %d integer\n",sum,i);
        }

    }

return 0;
}