#include<stdio.h>

int main(void)
 {
   float principal, rate, interest;
   int years;
   printf("principal, rate, and years? ");

   scanf("%f %f %d", &principal, &rate, &years);

   rate /= 100;
   interest = principal * rate * years;
   printf("interest = %f\n", interest);

   return 0;
 }