#include <stdio.h>

int main(void)
{
        float change = -0.1;
        int i = 0;
        do {
                printf("O hai! How much change is owed? ");
                scanf("%f", &change);
        }while(change <= -0.1);

        for (i = 0; change > 0.00; i++) {
                if(change >= 0.25)
                        change -= 0.25;
                else if(change >= 0.10)
                        change -= 0.10;
                else if(change >= 0.05)
                        change -= 0.05;
                else change -= 0.01;
        }
        printf("%d\n", i);

return 0;
}