OJ Board

Can anyone tell me why am i getting WA


#include<stdio.h>
#include<string.h>
int main()
{
int i,j,len=0,k;
char ch[30];
freopen("resent.txt","r",stdin);
freopen("ot.txt","w",stdout);
char str[20][1][30];
for(i=0;i<10;i++)
{
for(j=0;j<30;j++)
{
str [0][j]='\0';
}
}
j=0;
while(gets(ch ...