Compilare: main.cpp: In function 'int main()': main.cpp:9:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=n;i++) ~^~~ main.cpp:10:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<=m;j++) ~^~~ main.cpp:12:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=n;i++) ~^~~ main.cpp:13:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(j=1;j<=m;j++) ~^~~ main.cpp:16:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(x=1;x<=m;x++) ~^~~ main.cpp:20:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<=m;j++) ~^~~ main.cpp:22:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=n;i++) ~^~~ main.cpp:25:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(x=1;x<=n;x++) ~^~~ main.cpp:30:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=n;i++) ~^~~ main.cpp:31:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<=m;j++) ~^~~