# include<stdio.h>
int main()
{
    int sign=1;
    float term,demo=2.0,sum=1.0;
    while(demo<=100)
    {
    sign=-sign; 
    term=sign/demo;
    sum=sum+term;
    demo=demo+1;
     }
   printf("%f\n",sum);
   getchar();
}