diff --git a/du4/program.c b/du4/program.c
index cb5479c..f5f403d 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -51,6 +51,7 @@ for(;eof!=EOF;count++){
             ind++;
         }
     }
+	if(eof==EOF) break;
     sscanf(str,"%lF%c%lF=%lF ",&a,&ac,&b,&c);
     switch(ac){
         case '+':