UVA : 458-The Decoder

Link#458-The Decoder
#include <stdio.h>
#include <string.h>

int main()
{
   char a[1000];
   int l,i;
   while(gets(a)){
        l=strlen(a);
        for(i=0;i<l;i++){
                if(a[i]=='\n'){
                    printf("\n");
                }
                else{
                    printf("%c",a[i]-7);
                }
        }
        printf("\n");
   }
    return 0;
}