Error(s):

796286361/source.c:18:5: warning: return type defaults to ‘int’ [-Wimplicit-int]
     main()
     ^~~~
796286361/source.c:18:5: error: redefinition of ‘main’
796286361/source.c:6:5: note: previous definition of ‘main’ was here
 int main(void)
     ^~~~
796286361/source.c: In function ‘main’:
796286361/source.c:27:16: error: stray ‘\342’ in program
         system(“PAUSE”);
                ^
796286361/source.c:27:17: error: stray ‘\200’ in program
         system(“PAUSE”);
                 ^
796286361/source.c:27:18: error: stray ‘\234’ in program
         system(“PAUSE”);
                  ^
796286361/source.c:27:24: error: stray ‘\342’ in program
         system(“PAUSE”);
                        ^
796286361/source.c:27:25: error: stray ‘\200’ in program
         system(“PAUSE”);
                         ^
796286361/source.c:27:26: error: stray ‘\235’ in program
         system(“PAUSE”);
                          ^
796286361/source.c:27:19: error: ‘PAUSE’ undeclared (first use in this function)
         system(“PAUSE”);
                   ^~~~~
796286361/source.c:27:19: note: each undeclared identifier is reported only once for each function it appears in
796286361/source.c:22:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&a);
         ^~~~~~~~~~~~~~
796286361/source.c:24:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&b);
         ^~~~~~~~~~~~~~