Grunt-contrib-uglify Error Message

D:\Varun\GruntExamples\uglifyexample>grunt uglify
Running "uglify:mytarget" (uglify) task
{ message: 'Unexpected token: operator (<)',
  line: 1,
  col: 0,
  pos: 0,
  stack: 'Error\n    at new JS_Parse_Error (D:\\Varun\\GruntExamples\\uglifyexam
ple\\node_modules\\grunt-contrib-uglify\\node_modules\\uglify-js\\lib\\parse.js:
196:18)\n    at js_error (D:\\Varun\\GruntExamples\\uglifyexample\\node_modules\
\grunt-contrib-uglify\\node_modules\\uglify-js\\lib\\parse.js:204:11)\n    at cr
oak (D:\\Varun\\GruntExamples\\uglifyexample\\node_modules\\grunt-contrib-uglify
\\node_modules\\uglify-js\\lib\\parse.js:663:9)\n    at token_error (D:\\Varun\\
GruntExamples\\uglifyexample\\node_modules\\grunt-contrib-uglify\\node_modules\\
uglify-js\\lib\\parse.js:671:9)\n    at unexpected (D:\\Varun\\GruntExamples\\ug
lifyexample\\node_modules\\grunt-contrib-uglify\\node_modules\\uglify-js\\lib\\p
arse.js:677:9)\n    at expr_atom (D:\\Varun\\GruntExamples\\uglifyexample\\node_
modules\\grunt-contrib-uglify\\node_modules\\uglify-js\\lib\\parse.js:1173:9)\n
   at maybe_unary (D:\\Varun\\GruntExamples\\uglifyexample\\node_modules\\grunt-
contrib-uglify\\node_modules\\uglify-js\\lib\\parse.js:1334:19)\n    at expr_ops
 (D:\\Varun\\GruntExamples\\uglifyexample\\node_modules\\grunt-contrib-uglify\\n
ode_modules\\uglify-js\\lib\\parse.js:1369:24)\n    at maybe_conditional (D:\\Va
run\\GruntExamples\\uglifyexample\\node_modules\\grunt-contrib-uglify\\node_modu
les\\uglify-js\\lib\\parse.js:1374:20)\n    at maybe_assign (D:\\Varun\\GruntExa
mples\\uglifyexample\\node_modules\\grunt-contrib-uglify\\node_modules\\uglify-j
s\\lib\\parse.js:1398:20)' }

>> Uglifying source "src/1.js,src/2.js,src/3.js" failed.
Warning: Uglification failed.
Unexpected token: operator (<).
Line 1 in src/1.js,src/2.js,src/3.js
 Use --force to continue.

Aborted due to warnings.