diff --git a/du4/program.c b/du4/program.c
index 844526d..cca935e 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -22,8 +22,12 @@ int main(){
 char *start=priklad, *end=NULL; 
 
 for(int c=0;c<count;c++){
-    int skip=0; 
+    int skip=0,znak=0; 
     for(int idx=0;start[idx]!='\n';idx++){
+	
+	if(start[idx]!='+'&&start[idx]!='-'&&start[idx]!='*'&&start[idx]!='/'){
+	    znak=1;
+	}
 	if((start[idx]<'0'||start[idx]>'9')&&start[idx]!=' '&&start[idx]!='='&&start[idx]!='+'&&start[idx]!='-'&&start[idx]!='*'&&start[idx]!='/'&&start[idx]!='.'){
 	    skip=1;
 	    printf("CHYBA\n");
@@ -32,7 +36,7 @@ for(int c=0;c<count;c++){
 	    break;
 	}
     }
-    if(skip==1){
+    if(skip==1||znk==0){
 	continue;
     }
     float num1=strtof(start,&end);