OJ Board

pls help.. got WA.. i dont know what's wrong :(

#include<cstdio>
int a,b,c,d;
int main(){
while(scanf("%d",&a)!=EOF){
if(a==0) printf(" 0 -> 1\n");
else{
c=1;
for(b=1;b<=a;b++){
c=c*b;
while(c%10==0){
c=c/10;
}
while(c>=100){
c=c%100;
}
}
d=c%10;
printf("%5d -> %d\n",a,d ...