/in/foo.c: In function 'main':
/in/foo.c:5:8: error: expected ')' before '>=' token
 int n(n>=1&&n<=50);
        ^~
/in/foo.c:9:1: error: expected '(' before '{' token
 {
 ^
/in/foo.c:10:4: warning: right-hand operand of comma expression has no effect [-Wunused-value]
 i=1,i<=n,i++;
    ^
/in/foo.c:17:10: warning: format '%d' expects argument of type 'int', but argument 2 has type 'double' [-Wformat=]
 printf("%d",sum);
          ^