Error(s):

source_file.c: In function ‘main’:
source_file.c:22:13: error: expected ‘;’ before ‘}’ token
             }
             ^
source_file.c:25:13: error: expected expression before ‘else’
             else
             ^
source_file.c:7:22: warning: variable ‘ch1’ set but not used [-Wunused-but-set-variable]
     int a,b,c,d,n,ch,ch1;
                      ^
source_file.c:7:13: warning: variable ‘c’ set but not used [-Wunused-but-set-variable]
     int a,b,c,d,n,ch,ch1;
             ^
source_file.c:9:5: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ^