POJ 2720:大象喝水

#include<stdio.h>int main(){    int a,b,d,i;    float c;    scanf("%d %d",&a,&b);    c=a*3.14159*b*b;    d=20000/c;    if(20000-c*d>0)    d=d+1;    else    ;    printf("%d",d);    return 0;}