#include <stdio.h>

int main(int argc, char *argv[]) {

  float temp;
  char unit;

  printf("Enter temp and unit (25.0 C) ");

  scanf("%f %c", &temp, &unit);
  if (unit == 'C' || unit == 'c') {
    printf("%.2fC is ", temp);
    temp = temp * (9.0 / 5.0) + 32.0;
    printf("%.2fF\n", temp);
  } else if (unit == 'F' || unit == 'f') {
    printf("%.2fF is ", temp);
    temp = (temp - 32.0) * 5.0 / 9.0;
    printf("%.2fC\n", temp);
  } else {
    printf("Unknown temperature unit. Use C or F\n");
  }

  return 0;
}