/in/foo.cc: In function 'int main()':
/in/foo.cc:8:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=n-1;a++)
         ^
/in/foo.cc:14:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=n-i;a++){
         ^
/in/foo.cc:19:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=2*i-3;a++){
         ^
/in/foo.cc:28:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=n-1;a++)
         ^
/in/foo.cc:34:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=i;a++){
         ^
/in/foo.cc:39:9: warning: statement has no effect [-Wunused-value]
    for(a;a<=2*(n-i-1)-1;a++){
         ^