#include <stdio.h>

int main()

{

int i,dot;

char s[105];

while(scanf("%s",s)==1)
{
for(i=0;s[i]!='.';i++);
dot = i;
if(s[dot+3]>'4')
s[dot+2]++;
for(i=dot+2;i>-1;i--)
{
if(s[i]!='.' && s[i]!='-')
{
if(s[i]==58)
{
s[i] = 48;
if(s[i-1] != '.')
s[i-1]++;
else
s[i-2]++;
}
else
break;
}
}
s[dot+3] = '\0';
if(s[1]==s[3] && s[3]==s[4] && s[4]=='0')
printf("%s\n",s+1);
else
printf("%s\n",s);
}
return 0;
}

http://ghaouse.blogspot.com/2011/08/d561.html