Main.cc: In function 'int main()':
Main.cc:9:24: error: 'n' was not declared in this scope
for(int i,j=1;i,j<=n;i,j=i,j+1)
^
Main.cc:9:30: warning: left operand of comma operator has no effect [-Wunused-value]
for(int i,j=1;i,j<=n;i,j=i,j+1)
^
Main.cc:9:33: warning: right operand of comma operator has no effect [-Wunused-value]
for(int i,j=1;i,j<=n;i,j=i,j+1)
^