#C <del>168</del> 145 bytes

**145**

 i,a;main(b){for(;~scanf("%c",&b);printf(" %c"+!!i,b),a=a*21+b-100,++i)if(i>4|a==204488|a==5062|a==7466|a==23744|a==21106|a==6740|a==95026)a=i=0;}

[Try it online][1]

**168**

 i,a;main(b){for(;~scanf("%c",&b);printf(" %c"+!!i,b),a|=b<<8*i++)if(i>4|a==1869768058|a==6647407|a==7305076|a==1920298854|a==1702259046|a==7891315|a==1701734766)a=i=0;}

[Try it online!][2]

Ungolfed 

 i,a;main(b){
 for(;~scanf("%c",&b); // for every char of input
 printf(" %c"+!!i,b), // print whitespace if i==0 , + char
 a|=b<<8*i++ // add char to a for test
 )
 if(
 i>4| // three seven eight
 a==1869768058| // zero
 a==6647407| // one
 a==7305076| // two
 a==1920298854| //four
 a==1702259046| //five
 a==7891315| //six
 a==1701734766 //nine
 ) a=i=0; //reset i and a
 }

int constants gets unnecessary large by shifting a<<8 
but in case you can compare to strings somehow it should be the most natural

[String comparison works but got longer][3]


 [1]: https://tio.run/##PY1dDsIgEISvoiaaYjGhFammwbtQsug@CIbW2vh39QrU@MIM38zu6s1J63FEquqLQps15Gmcz@pPq5U12WKpF3TVkPrq0XbhPwsgn8@RNoQqqdZlkTebgjGa50jQZHjkLyVlyTjf76PbMVFGrbgQKdlWfKoUBUtEVJxFPexYKYiSKFn9HkeDPXRnDxBNi0PyFi04Cy30YIMCns5dChKZHhyMu/kgU3p3/00JPMC7MBr4tD10fxfSeOrEM18
 [2]: https://tio.run/##PU3bbsMgDP2VtdKmsGQSSQCDUvYvBEHrh8FE0ou2br@eEVLtxT4@N9u3o7XLgo0ZPgyGaiTfPqZq@J2sCb7aP9t98zKS4TNhmPP9lIl6t8NmJI256/FwkK9Y1wR9he/sbrRupVAgJOVyvYRgwCisEHrKKYjiUR3tlJR8SwDtOq4oKxpI1fYtfwgt9AyEIEajpsPPsni8uPmUnFvBhLeCAwYXg5vcxYW8HR5PcxEKsw28@XhOeW3qNf43FeLLpZijmd/as/fxocSLZ33zBw
 [3]: https://tio.run/##LY3BbsIwDIbve4rSiSlpMwmhHSaV8CLTDmnmgA8kKAlQAdurd3bSi/379@ff9v1g7Ty//oBDD00Sk2xSjvZ0FkZN8gWV@dp@DyeDXozy4UIUw1@yxjvRrm2r3kY5nCP6THNDRr9aoRql6sxTj7vdZ4d9L9EJ3H88k2jvEEMrO1LBQxX5tjguXOKi8LosE05VeGRe643sjEa9GX7nmTEOzMcIwAPRRTNM@Qmu4KkDHo65LIpTC078j1rd3gIHFKgYnEun5Nd0YpcP5bww/OYf