/in/foo.c: In function 'main':
/in/foo.c:24:20: warning: unused variable 't' [-Wunused-variable]
  int n,min,sec,i,j,t,sum=0;
                    ^
/in/foo.c:24:18: warning: unused variable 'j' [-Wunused-variable]
  int n,min,sec,i,j,t,sum=0;
                  ^
/in/foo.c:24:12: warning: unused variable 'sec' [-Wunused-variable]
  int n,min,sec,i,j,t,sum=0;
            ^~~
/in/foo.c:24:8: warning: unused variable 'min' [-Wunused-variable]
  int n,min,sec,i,j,t,sum=0;
        ^~~